Process for producing a polymer by polymerization of a monomer having an ethylenic double bond

ABSTRACT

An improved process for producing a polymer by polymerizing a monomer having an ethylenic double bond in a polymerization vessel having a polymer scale preventive coating film on its inner wall surfaces, etc. is provided. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugated π bonds and a heterocyclic compound having 5 or more conjugated πbonds, and then coating a second coating liquid a dye and/or pigment on the first layer. The first and second coating liquids are applied by means of steam as a carrier. The second layer has a surface having a contact angle to water of less than 60° after its surface has been kept in contact with a solution of mixture of water and a vinyl chloride monomer in a weight ratio of 1:1 at 50° C. for 1 hour. This process can shorten the time for forming the coating film to improve productivity, can improve the effect of preventing adhesion of polymer scale, can make colored particles less mix into polymer products obtained by this process, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process for producing a polymer bypolymerizing in a polymerization vessel a monomer having an ethylenicdouble bond, and particularly a process that can prevent polymer scalesfrom adhering to polymerization vessel inner wall surfaces and othersand can produce polymers having a good quality.

2. Description of the Prior Arts

As known in processes for producing polymers by polymerizing monomers inpolymerization vessels, there is a problem that polymers may adhere topolymerization vessel inner wall surfaces and others in the form ofscales.

Such polymer scales having adhered to polymerization vessel inner wallsurfaces and others may cause a decrease in yield of polymers, adecrease in cooling capacity of polymerization vessels, and a loweringof product quality when polymer scales having adhered come off to mixinto polymer products, and also may bring about a disadvantage that muchlabor and time must be taken to remove the polymer scales.

Moreover, since the polymer scales contain unreacted monomers, there isa possibility that operators are exposed to them to cause physicaldisorder.

Accordingly, in the polymerization of monomers having ethylenic doublebonds, in order to prevent polymer scales from adhering topolymerization vessel inner wall surfaces and others, methods ofpreventing the adhesion of polymer scales by one-stage coating(hereinafter “one-stage coating method”) are proposed, as exemplified bya method in which a polar organic compound such as an amine compound, aquinone compound or an aldehyde compound or a dye or pigment is coatedas a “polymer scale preventive agents” on polymerization vessel innerwall surfaces, stirrers and so forth (Japanese Patent Publications(kokoku) Nos. 45-30343 and 45-30835), a method in which a polar organiccompound or dye treated with a metal salt is coated (Japanese PatentPublication (kokoku) No. 52-24953, a method in which a mixture of anelectron-donating compound and an electron-accepting compound is coated(Japanese Patent Publication (kokoku) No. 53-28347), a method in which acondensation reaction product of 1-naphthol with formaldehyde is coated(Japanese Pre-examination Patent Publication (kokai) No. 57-164107), amethod in which a condensation reaction product of a phenol compoundwith formaldehyde is coated (Japanese Pre-examination Patent Publication(kokai) No. 57-192413), a method in which a polyaromatic amine is coated(Japanese Patent Publication (kokoku) No. 59-16561), a method in which aself-condensation product of a polyhydric phenol or a self-condensationproduct of a polyhydric naphthol is coated (Japanese Pre-examinationPatent Publication (kokai) No. 54-7487), a method in which acondensation reaction product of a ketone resin with a phenol compoundis coated (Japanese Pre-examination Patent Publication (kokai) No.62-236804), a method in which a condensation reaction product of anaromatic amine with an aromatic nitro compound and a material obtainedby making the compound basic are coated (Japanese Patent Publication(kokoku) No. 60-30681), and a method in which a condensation reactionproduct of an aromatic amine with a quinone compound is coated (JapanesePre-examination Patent Publication (kokai) No. 61-7309).

In the case of polymer scale preventive coating films obtained by suchone-stage coating methods, scales tend to adhere to the vicinity of agas-liquid boundary surface in the polymerization vessel duringpolymerization, or, depending on the composition of a polymerizationreaction mixture, scales tend to adhere to the whole wall surface.Accordingly, to prevent this, it is known to mix in a coating liquidcontaining the polymer scale preventive agent a water-soluble polymericcompound such as an anionic polymeric compound, an amphoteric polymericcompound, a cationic polymeric compound or a hydroxyl-group-containingpolymeric compound; an inorganic colloid; or a substance having noaffinity for monomers, as exemplified by an inorganic salt such as analkali metal salt (hereinafter “polymer scale preventive auxiliaryagents”). These one-stage coating methods are effective for preventingthe adhesion of polymer scales when monomers having ethylenic doublebonds are polymerized in polymerization vessels.

In instances where no sufficient polymer scale prevention effect can beobtained by the one-stage coating method, a method of preventing theadhesion of polymer scales by two-stage coating (hereinafter “two-stagecoating method”) is proposed, which comprises a) coating a coatingliquid containing the polymer scale preventive agent as described above,to form a first layer, and b) coating further thereon a coating liquidcontaining the above polymer scale preventive auxiliary agent, to form asecond layer (Japanese Pre-examination Patent Publication (kokai) Nos.3-74404, 2-80403, 2-80402, 2-80401 and 2-47102).

In both the above one-stage coating method and two-stage coating methodfor preventing the adhesion of polymer scales, spray coating is usuallyused as a coating process in view of productivity including operability.

In the one-stage coating method of coating the polymer scale preventiveagent by spray coating, the coating film is formed by a processcomprising the following steps 1 to 3. Step 1: A coating liquidcontaining the polymer scale preventive agent is coated on thepolymerization vessel inner wall surface and other surfaces with whichmonomers come into contact. Step 2: The coated surfaces are dried toform a dry film. Step 3: The surface of the coating film thus formed iswashed to remove any excess coating liquid.

In the two-stage coating method comprising coating the polymer scalepreventive agent and coating the polymer scale preventive auxiliaryagent both by spray coating, the coating film formation comprising thesame steps 1 to 3 as the above is operated also in the second-stagecoating.

When the above spray coating is used, the surfaces of baffles andstirring blades that face polymerization vessel inner wall surfacesstand within the dead angle from a spray nozzle. Since it is hard forthe coating liquid to reach the surfaces of such portions standing blindor hidden from the spray nozzle, the polymer scale preventive agent cannot be coated thereon in the same way as on the surfaces not standingblind. Thus, it is difficult to form a uniform coating film over thesurfaces standing blind and the surfaces not standing blind. If acoating film in a quantity effective enough to prevent the adhesion ofpolymer scales is intended to be formed also on the blind surfaces, itis inevitable to use a coating liquid containing the polymer scalepreventive agent in a larger quantity than that for the other surfaces.It follows that an unnecessarily excess preventive agent is applied onthe surfaces not standing blind. Hence, the coating film thus formedhave had an uneven coating thickness and the coating film have had alarger thickness locally than is necessary.

The formation of polymer scale preventive coating films by spray coatinghas also had the following problems.

(1) Usually, the coating film comprising the polymer scale preventiveagent is formed previously for each polymerization batching. Since it iscommon for the polymer scale preventive agent to have a color, thepolymer scale preventive agent is repeatedly coated as thepolymerization is batched repeatedly in a larger number, so that thecoating film may have a large thickness at some part. The part havingsuch a thick coating film may come off to become included into thereaction mixture, or the scale preventive agent may be coated on polymerscales having already adhered to the polymerization vessel inner wallsurfaces and others and may come off together with a part of the scalesto mix into the resultant polymerization products. This may causecolored particles or fish eyes brought in their formed products or maycause a low product quality such as a high initial discoloring of formedproducts, disadvantageously.

(2) As stated above, the effect of preventing adhesion of polymer scalesat the surfaces standing blind or hidden in the polymerization vessel,standing within the dead angle from the spray nozzle, can not be said tobe so much sufficient, considering the polymer scale preventive agentapplied in a fairly larger quantity than that on other surfaces.

(3) The spray coating requires a drying step of drying the coatedsurfaces, and takes a time necessary for forming the coating film of thepolymer scale preventive agent. Accordingly, in respect of animprovement of productivity, it is sought to shorten the time necessaryfor forming the coating film.

As a measure for eliminating the above disadvantages in the spraycoating, a method is proposed in which a coating liquid containing apolymer scale preventive agent is coated using steam as a carrier(hereinafter “steam coatings”) (Japanese Patent Publication (kokoku) No.1-5044. As the coating liquid in this method, used is a coating liquidcomprised of the polymer scale preventive agent alone or a coatingliquid to which the polymer scale preventive auxiliary agent is furtheradded.

This steam coating has the following advantages.

(1) A thin and uniform coating film of the polymer scale preventiveagent, necessary for preventing the adhesion of scales effectively canbe formed using the coating liquid in a small quantity.

(2) The coating film of the polymer scale preventive agent, necessaryfor achieving the scale prevention effect can be formed using thecoating liquid in a small quantity, also on the portions standing blindor hidden in the polymerization vessel, standing within the dead anglefrom the spray nozzle. Thus, the polymer scale prevention effect can beattained also on these portions.

(3) The drying step is unnecessary in the coating film forming step, sothat the time necessary for forming the coating film of the polymerscale preventive agent can be shortened.

Incidentally, in the steam coating, the coating liquid and steam aremixed so that the coating liquid is carried by the steam and can beapplied to the polymerization vessel inner wall surfaces and others.Accordingly, the concentration of the polymer scale preventive agent inthe coating liquid is set taking account of the fact that the solutionis diluted with steam. Usually, the concentration of the polymer scalepreventive agent in the coating liquid for steam coating is set 4 to 40times that of the one for spray coating, although the amount of apolymer scale preventive agent necessary in steam coating isapproximately equivalent to that necessary in spray coating.

In contrast to the advantages, the steam coating has problems on thefollowing points.

(1) Although the steam coating enables uniform coating in apolymerization vessel, the deposition of scale can be preventedinsufficiently around the interface between the gas-liquid phases.

(2) As the result of the insufficient prevention of scale depositionaround the interface between gas-liquid phases, the polymer scaledeposition will grow around the interface with repetition ofpolymerization runs. A part of the grown deposited scale may peel offthe inner surfaces of the polymerization vessel during polymerizationand be incorporated into a polymer product to cause formation offisheyes.

(3) A polymer scale preventive agent is coated on the inner surfaces ofa polymerization vessel repeatedly as polymerization runs are repeated.Consequently, the layer of the polymer scale preventive agent becomethicker gradually. A part of the thick layer of the agent may peel offduring polymerization and be incorporated into polymer products to causecolored particles. The colored particles will lower anti-initialdiscoloration properties, particularly luminosity index L, of polymerproducts.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a process for producinga polymer by polymerizing a monomer having an ethylenic double bond,which can shorten the time for forming coating films of polymer scalepreventive agents to improve productivity, can improve the effect ofpreventing adhesion of polymer scales, can make colored particles lessmix into polymer products obtained by this process, can lessen fish eyesand initial discoloring of formed products and can improve the qualityof polymeric products and their formed or molded products.

The above subject can be settled by a process for producing a polymer bypolymerizing in a polymerization vessel a monomer having an ethylenicdouble bond, wherein

said polymerization vessel has a polymer scale preventive coating filmon its inner wall surfaces and other surfaces with which the monomercomes into contact during polymerization;

said coating film comprising a first layer formed on said inner wallsurfaces and other surfaces and a second layer formed on the firstlayer;

said first layer being formed by coating a first coating liquidcontaining a compound selected from the group consisting of an aromaticcompound having 5 or more conjugated π bonds and a heterocyclic compoundhaving 5 or more conjugated π bonds by means of steam as a carrier, andsaid second layer being formed by coating a second coating liquid on thefirst layer by means of steam as a carrier; and

said second layer containing at least one member selected from the groupconsisting of dyes and pigments and having a surface having a contactangle to water of less than 60° after its surface has been brought intocontact with a solution of the mixture of water and a vinyl chloridemonomer in a weight ratio of 1:1, at 50° C. for 1 hour.

According to the polymerization process of the present invention, thetime for forming coating films of polymer scale preventive agents can beshortened to improve productivity, and also, when monomers having anethylenic double bond are polymerized, polymer scales can be preventedeffectively from adhering to not only wall surfaces at the liquid-phaseportion in the polymerization vessel but also stirrers, baffle surfacesfacing the wall surface, and the vicinity of the boundary surfacebetween the gaseous phase and the liquid phase. Hence, the quality ofpolymer products can be improved and the colored particles can be madeless mix into polymers, and also formed products obtained by forming thepolymers into sheets can be made to have very less fish eyes and alsohave good anti-initial discoloring.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings,

FIG. 1 schematically illustrates the arrangement in a polymerizationapparatus; and

FIG. 2 schematically illustrates the arrangement in anotherpolymerization apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described below in detail. In thefollowing, the polymer scale preventive agent is often called simply as“scale preventive agents”.

The scale-preventive coating film formed in the present inventioncomprises a first layer formed on the polymerization vessel inner wallsurfaces and others and a second layer formed on the first layer.

[Coating-Film First Layer]

The aromatic compound and heterocyclic compound used in the first-layerforming coating liquid each have 5 or more conjugated π bonds. In thepresent specification, the term “π bonds” is meant to be double bondsand triple bonds, including, e.g., C═C, C≡C, N═N, C═N, C═S and C═O, andthe term “conjugated π bonds” is meant to be a series of π bonds whereineach pair of adjacent π bonds are connected to each other through asingle bond and all of the π bonds have a mutually conjugatedrelationship with each other. The aromatic compound having 5 or moreconjugated π bonds and the heterocyclic compound having 5 or moreconjugated π bonds are herein called together generically as “conjugatedπ bond compound” in some cases. The 5 or more π bonds are present in theconjugated π bond compound may form a single conjugation group or two ormore conjugation groups.

Aromatic compound having 5 or more conjugated π bonds:

The aromatic compound having 5 or more conjugated π bonds may includebenzene derivatives, naphthalene derivatives, polynuclear aromaticcompounds, quinones, non-benzene type aromatic compounds, and aromaticcompound condensation products having a weight-average molecular weight,which term herein means weight-average molecular weight in terms ofpolystyrene as measured by gel permeation chromatography, of 500 ormore.

First, as benzene derivatives, there may be included:

phenols and derivatives thereof, such as 3,7-dihydroxy-10-methylxantheneand hydroxyanthraquinone;

aromatic amines and derivatives thereof, such as quinoline, carbazole,o-phenanthroline, p-phenanthroline, 3,6-diaminoacridine,3-aminophenothiazine, 2-aminophenazine, phenothiazine,2-hydroxy4-methyl-quinoline;

nitro and nitroso derivatives, such as phenazine, phenazine oxide,1-phenylazo-2-naphthol, triphenylendioxadine and 4-nitroxanthone;

aromatic aldehydes, such as benzoflavin;

benzene derivatives having further one substituent other than aldehydegroup, such as 1-hydroxy2,4-methyl-fluorone, 3-phenylcoumarone, ethylcoumarine-3-carboxylate, 3-acetylcoumarine,5-chloro-3-(4-hydroxyphenyl)anthranyl and 3-nitroacridone;

benzene derivatives having further one substituent other than acylgroup, such as xanthone, 2-benzoylxanthone, xanthene and fluorene;

benzene derivatives and toluene derivatives having three or moredifferent substituents, such as7-acetoxy-8-methoxy-3-(2-nitrophenyl)carbostyryl; and

aralkyl compounds, such as 9-benzylacridine;

diazo compounds and azo compounds, such as 1,1′-azonaphthalene andazoxyphenol.

Next, as naphthalene derivatives, there may be included:

alkyl, alkenyl and phenylnaphthalenes, such as 2-methylnaphthalene,1-ethyl-naphthalene, 2-ethylnaphthalene and 1,2-dimethylnaphthalene;

dinaphthyls, such as 1,1′-dinaphthyl, 1,2′-dinaphthyl and2,2′-dinaphthyl;

naphthylarylmethanes, such as 1-benzylnaphthalene, 2-benzylnaphthalene,1-(α,α-dichlorobenzyl)naphthalene, diphenyl-α-naphthyl-methane,diphenyl-β-naphthylmethane and di-α-naphthylmethane;

naphthylarylethanes, such as 1,2-di-α-naphthylethane and1,2-di-β-naphthylethane;

hydronaphthalenes such as 1,2-dihydronaphthalenes,1,4-dihydronaphthalene and 1,2,3,4-tetrahydronaphthalene;

nitronaphthalenes and derivatives thereof, such asnitromethyl-naphthalene, nitroalkylnaphthalene, nitrophenyl-naphthalene,halo-nitronaphthalene, halo-dinitro-naphthalene, nitrosonaphthalene,diaminonaphthalene, triaminonaphthalene and tetraaminonaphthalene;

halogenated naphthalenes, such as 1-fluoro-naphthalene,1-chloronaphthalene and 1-chloro-3,4-dihydronaphthalene;

naphthylhydroxylamines, naphthylpyrazines and naphthylureas, such asα-naphthylhydroxylamine, β-naphthylthiohydroxyl-amine,N-nitroso-α-naphthylhydroxylamine, α-naphthylhydrazine and1,2-dibenzocarbazole;

naphthalene-based aralkyl compounds, such as dibenzoanthracene,acenaphthene, diphenyl-naphthylchloromethane and nitromethylnaphthalene;

naphthoaldehydes and derivatives thereof, such as α-naphthoaldehyde and2-(2,4-dinitrophenyl)-1-(α-naphthyl)-ethylene;

acetonaphthenes and benzoylnaphthalenes, such as1,2;5,6-dibenzanthracene, 2′-methyl-2,1′-dinaphthyl ketone,2-methyl-1,1′-dinaphthyl ketone and styryl-2-naphthyl ketone.

As the polynuclear aromatic compounds, there may be included:

anthracenes and derivatives thereof, such as anthracene,1,2-dihydroanthracene, 1-chloroanthracene, 1,4-dichloroanthracene,1-nitroanthracene, 9,10-dinitroanthracene, 1-aminoanthracene,2-dimethyl-aminoanthracene, 2-anilinoanthracene,9-methylaminoanthracene, 1,4-diaminoanthracene;

phenanthrenes and derivatives thereof, such as phenanthrene,9,10-dihydrophenanthrene, 1,2,3,4-tetrahydrophenanthrene and1-chlorophenanthrene;

phenanthrenequinones, such as phenanthrene-1,2-quinone andphenanthrene-1,4-quinone; and

polynuclear aromatic compounds and derivatives thereof, such aspentacene, hexacene, benzophenanthrene, benzo[a]anthracene, pyrene andcoronene.

As quinones and derivatives thereof, there may be included:

naphthoquinones and derivatives thereof, such as 1,2-naphthoquinone,3-hydroxy-2,2′-binaphthyl-1,4;3′,4′-diquinone, 5,6-benzoquinoxaline,1,2-benzophenazine, 2-benzoazo-1-naphthol,4-(2,4-dihydroxyphenyl)-1,2-dihydroxynaphthalene,4-(3,4,5-trihydroxyphenyl)-1,2-dihydroxynaphthalene and 1,4-naphthol;and

anthraquinones and derivatives thereof, such as 1,2-anthraquinone,2,3-anthraquinone, 1,4-anthraquinone, alizarin, quinizarin, chrysazin,hystazarin, anthraflavin, isoanthraflavin, anthragallol, purpurin,hydroxyanthrarufin, hydroxychrysazin, hydroxyflavopurpurin, quinazarinand alizarinpentacyanine.

Further, as the non-benzene aromatic compounds, there may be included,for example, azulene, cyclodecapentane, cyclotetradecaheptane,cyclooctadecanonaene, cyclotetracosadodecaene, heptalene, fulvalene,sesquiflulvalene, heptafluvalene and perinaphthene.

The aromatic compound condensation products having a molecular weight of500 or more may suitably be aromatic compound condensation productshaving preferably a weight-average molecular weight of from 500 to70,000, and more preferably from 1,500 to 30,000.

Preferred aromatic compound condensation products include the compoundsbelow, for instance.

Aldehyde compound/aromatic hydroxyl compound condensation products

The aldehyde compound/aromatic hydroxyl compound condensation product isa condensation product of an aldehyde compound with an aromatic hydroxylcompound. The use of such aldehyde compound/aromatic hydroxyl compoundcondensation products in polymer scale preventive agents are disclosedin, for example, Japanese Pre-examination Patent Publication (kokai)No.57-192413, Japanese Patent Publication (kokoku) No. 6-62709, JapanesePre-examination Patent Publication (kokai) No. 57-164107 and WO98/24820.

The aldehyde compounds include, for example, formaldehyde, acetaldehyde,propionaldehyde, butylaldehyde, acrolein, crotonaldehyde, benzaldehyde,furfural, phenylacetaldehyde, 3-phenylpropionaldehyde and2-phenylpropionaldehyde. From industrial and economical viewpoints,formaldehyde and acetaldehyde are advantageous.

The aromatic hydroxyl compounds include, for example, dihydroxybiphenylcompounds, naphthol compounds, phenol compounds, tannins and dimericcompounds of 2,3-dihydroxynaphthalene.

Examples of the dihydroxybiphenyl compounds include2,2′-dihydroxybiphenyl, 2,2′-dihydroxy-5,5′-dimethylbiphenyl,2,2′-dihydroxy-4,4′,5,5′-tetramethylbiphenyl,2,2′-dihydroxy-5,5′-dichlorobiphenyl,2,2′-dihydroxy-5,5′-dichlorohexylbiphenyl and2,2′-dihydroxy-5,5′-di-tert-butylbiphenyl. In particular, from anindustrial viewpoint, 2,2′-dihydroxybiphenyl is preferred.

Examples of the naphthol compounds include 1-naphthol, 2-naphthol,1,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene,1,7-dihydroxynaphthalene, 6-hydroxy-2-naphthoic acid,2-hydroxy-1-naphthoic acid, 1-hydroxy-2-naphthoic acid and1-hydroxy-8-naphthoic acid.

Examples of the phenol compounds include phenol, cresol, pyrogallol,hydroxyhydroquinone, resorcin, catechol, hydroquinone, bisphenol-A,hydroxybenzoic acid, dihydroxybenzoic acid, 2-hydroxy-5-methoxybenzoicacid and salicylic acid.

Examples of the tannins include tannic acid, Chinese gallotannin,Turkish gallotannin, sumac tannin, quebracho tannin, and tannin ofpersimmon (shibuol).

The dimeric compounds of 2,3-dihydroxynaphthalene include, for example,2,3,2′,3′-tetrahydroxybinaphthyl.

The above condensation product of an aldehyde compound with an aromatichydroxyl compound can be produced by reacting these reactive componentsin a suitable medium in the presence of a catalyst, usually at roomtemperature to 200° C. for 2 to 100 hours, preferably at 30 to 150° C.for 3 to 30 hours. Each of the aromatic hydroxyl compound and thealdehyde compound can be used singly or in combination of two or morekinds.

The medium in which the above condensation reaction is carried outincludes, for example, water; and organic solvents, such as alcohols,ketones and esters. The organic solvents include, for example, alcohols,such as methanol, ethanol and propanol; ketones, such as acetone andmethyl ethyl ketone; and esters, such as methyl acetate and ethylacetate.

The medium in which the above condensation reaction is carried out has apH in the range of usually from 1 to 13, and pH adjusters may be usedwithout any particular limitations.

The catalyst used in the above condensation reaction includes, forexample, acidic catalysts, such as sulfuric acid, hydrochloric acid,perchloric acid, p-toluenesulfonic acid, methanesulfonic acid andtrifluoromethanesulfonic acid; and basic catalysts, such as NaOH, KOHand NH₄OH.

The ratio of the aldehyde to the aromatic hydroxyl compound used whenthe condensation reaction is carried out depends on the types of thealdehyde compound, aromatic hydroxyl compound, solvent and catalystused, the reaction time, the reaction temperature and so forth.Generally, it is preferable to use from 0.1 to 10 mols of the aldehydecompound per mol of the aromatic hydroxyl compound.

Pyrogallol/acetone condensation products

The pyrogallol/acetone condensation product is a condensation product ofpyrogallol with acetone, the molar ratio of the pyrogallol to theacetone being in the range of usually from 1/0.1 to 1/10, and themelting point thereof being usually from 100 to 500° C. The meltingpoint increases with an increase in molecular weights. For example,melting points of from 160 to 170° C. correspond to molecular weights offrom 1,450 to 1,650; and melting points of from 200 to 220° C., tomolecular weights of from 2,600 to 4,000. The use of suchpyrogallol/acetone condensation products in polymer scale preventiveagents is disclosed in, for example, Japanese Pre-examination PatentPublication (kokai) No. 4-328104.

The pyrogallol/acetone condensation product can be produced bydissolving pyrogallol in acetone, and condensing them in the presence ofa condensation catalyst. The pyrogallol is used in an amount of usuallyfrom 1 to 100 parts by weight per 100 parts by weight of the acetone. Asthe condensation catalyst, for example, phosphorus oxychloride is used.The reaction may be carried out at room temperature to 100° C.

Polyhydric phenol self-condensation products and

polyhdric naphthol self-condensation products

Polyhydric phenols are exemplified by catechol, resorcinol,chlororesorcinol, hydroquinone, phloroglucinol and pyrogallol;dihydroxytoluene and dihydroxyxylene; trihydroxy-toluene andtrihydroxyxylene; ethyl-di-, propyl-di-, butyl-di- orpentyl-di-hydroxybenzene; and trihydroxybenzene. Polyhydric naphtholsare exemplified by naphthol derivatives, such as 1,3-, 1,4-, 1,5- or1,7-dihydroxynaphthalene. The use of such polyhydric phenolself-condensation products and polyhydric naphthol self-condensationproducts in polymer scale preventive agents is disclosed in, forexample, Japanese Pre-examination Patent Publication (kokai) No.54-7487.

The polyhydric phenol self-condensation product or polyhydric naphtholself-condensation product can be produced by heating polyhydric phenolor polyhydric naphthol in an inert atmosphere, such as nitrogen, argonor the like, at a temperature ranging from 200 to 350° C. for 4 to 100hours. In this reaction, various catalysts may be used, as exemplifiedby zinc chloride, aluminum chloride and sodium hydroxide.

Aromatic amine compound condensation products

The aromatic amine compound condensation products include, for example;

(1) a self-condensation product of an aromatic amine compound;

(2) a condensation product of an aromatic amine compound with a phenolcompound;

(3) a condensation product of an aromatic amine compound with anaromatic nitro compound; and

(4) a basic product obtained by making basic a condensation product ofan aromatic amine compound with an aromatic nitro compound by the use ofan alkali metal salt or an ammonium compound.

The use of such aromatic amine compound condensation products isdisclosed in, for example, Japanese Patent Publication (kokoku) Nos.59-16561 and 60-30681.

The aromatic amine compounds are exemplified by aniline, o-, m- orp-phenylenediamine, o-, m- or p-aminophenol, o-, m- or p-chloroaniline,p-aminobenzene, 2,4-diaminoazobenzene, p-aminoacetanilide, o-, m- orp-methylaniline, N,N-dimethyl-p-phenylenediamine,4-chloro-o-phenylenediamine, 4-methoxy-o-phenylenediamine,2-amino-4-chlorophenol, 2,3-diaminotoluene, 2,4-diaminophenol, anddiphenylamines such as 4-aminodiphenylamine, 2-aminodiphenylamine,4,4′-diaminodiphenylamine, 4-amino-3′-methoxydiphenylamine and4-amino-4′-hydroxydiphenylamine.

The phenol compounds are specifically exemplified by phenol,hydroquinone, resorcinol, catechol, hydroxyhydroquinone, pyrogallol, o-,m- or p-chlorophenol, o-, m- or p-hydroxybenzoic acid,2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid,2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid,3,5-dihydroxybenzoic acid and 2,5-, 2,6- or 3,5-dihydroxytoluene.

The aromatic nitro compounds are exemplified by nitrobenzene, o-, m- orp-hydroxynitrobenzene, o-, m- or p-nitroanisole, o-, m- orp-nitrophenetole, o-, m- or p-chloronitrobenzene, o-, m- orp-aminonitrobenzene, o-, m- or p-nitrobenzoic acid, o-, m- orp-nitrobenzenesulfonic acid, o-, m- or p-nitroaniline,2-nitro-p-phenylenediamine, 2-amino-4-nitrophenol, 2-amino-5-nitrophenoland 4-amino-2-nitrophenol.

In order to carry out the self-condensation reaction of an aromaticamine compound alone, the condensation reaction of an aromatic aminecompound with a phenol compound and the condensation reaction of anaromatic amine compound with an aromatic nitro compound, a mineral acidand a condensation catalyst are used. The mineral acids are exemplifiedby hydrochloric acid, nitric acid, hydrobromic acid, phosphoric acid andsulfuric acid.

Preferable condensation catalysts are exemplified by permanganic acidand salts thereof, such as permanganic acid and potassium permanganate;chromic acid-related compounds, such as chromium trioxide, potassiumdichromate and sodium chlorochromate; metal nitrates, such as silvernitrate and lead nitrate; halogens, such as iodine and bromine;peroxides, such as hydrogen peroxide, sodium peroxide, benzoyl peroxide,potassium persulfate, ammonium persulfate, peracetic acid, cumenehydroperoxide, perbenzoic acid and p-menthane hydroperoxide; oxygenacids or oxygen acid salts, such as iodic acid, potassium iodate andsodium chlorate; metal salts, such as ferrous chloride, ferric chloride,copper sulfate, cuprous chloride, cupric chloride and lead acetate;ozone; and oxides, such as copper oxide, mercury oxide, cerium oxide,manganese dioxide and osmic acid. It is also effective to use hydrogenperoxide and ferrous chloride in combination.

The self-condensation reaction of an aromatic amine compound alone, thecondensation reaction of an aromatic amine compound with a phenolcompound and the condensation reaction of an aromatic amine compoundwith an aromatic nitro compound may be carried out in the presence of acondensation catalyst at 100 to 350° C. for 2 to 100 hours.

The ratio of an aromatic amine compound to a phenol compound or anaromatic nitro compound, which are used in the condensation reaction ofan aromatic amine compound with a phenol compound and the condensationreaction of an aromatic amine compound with an aromatic nitro compound,depends on the types of the aromatic amine compounds, phenol compoundsand aromatic nitro compounds and catalysts used, the reaction time, thereaction temperature and so forth. Generally, it is preferable to usefrom 0.1 to 10 mols of the phenol compound or the aromatic nitrocompound per mol of the aromatic amine compound.

In order to make basic a condensation product of an aromatic aminecompound with an aromatic nitro compound by the use of an alkali metalsalt or an ammonium compound, for example, 100 parts by weight of thecondensation product of an aromatic amine compound with an aromaticnitro compound is dispersed in water, 10 to 20 parts by weight of analkaline or ammonium compound, such as NaOH, KOH, Na₂CO₃, NH₄OH or(NH₄)₂CO₃ is added thereto, and the mixture obtained is heat treated at90 to 140° C. The alkali or ammonium compound may be used in an amountsufficient to neutralize the mineral acid used at the time of thecondensation reaction.

Quinone compound condensation products

The quinone compound condensation products include, for example, (A) aself-condensation product of a quinone compound, and (B) a condensationproduct of a quinone compound with at least one compound selected fromthe group consisting of an aromatic hydroxyl compound and an aromaticamine compound. The use of such quinone compound condensation productsin polymer scale preventive agents is disclosed in, for example,Japanese Pre-examination Patent Publication (kokai) Nos. 5-112603 and6-56911.

The quinone compounds include, for example, benzoquinones andderivatives thereof, such as o-, m- or p-benzoquinone, tolu-p-quinone,o-xylo-p-quinone, thymoquinone, 2-methoxybenzoquinone, gentisyl quinone,polyporic acid and ubiquinone-n; naphthoquinones and derivativesthereof, such as 6-methyl-1,4-naphthoquinone,2-methyl-1,4-naphthoquinone, α-naphthoquinone, juglone, lawsone,plumbagin, alkannin, echinochrome A, vitamin k₁, vitamin k₂, shikonin,β,β′-dimethyl acrylshikonin, β-hydroxyisovaleroshikonin andteracrylshikonin; anthraquinones and derivatives thereof, such astectoquinone, 3-hydroxy-2-methylanthraquinone, anthraquinone,2-hydroxyanthraquinone, alizarin, xanthopurpurin, rubiadin, munjistin,crysophanic acid, carminic acid, kermesic acid and laccaic acid A; andphenanthrenequinones such as phenanthrenequinone.

The aromatic amine compounds are specifically exemplified by aniline,o-, m- or p-phenylene-diamine, o-, m- or p-chloroaniline, o-, m- orp-methylaniline, N,N-dimethyl-p-phenylenediamine,4-chloro-o-phenylenediamine, 4-methoxy-o-phenylenediamine,2-amino-4-chlorophenol, 2,3-diaminotoluene, 4-amino-2-aminophenol, o-,m- or p-aminophenol, o-, m- or p-aminobenzoic acid, 2,3-, 2,4-, 2,5-,2,6-, 3,4-, 3,5- or 4,6-diaminobenzoic acid, 3- or 4-aminophthalic acid,2-, 4- or 5-aminoisophthalic acid, 4,6-diaminoisophthalic acid, 2,5- or2,6-diaminoterephthalic acid, 3-, 4- or 5-aminosalicylic acid,4-hydroxyanthranilic acid, o-, m- or p-aminobenzenesulfonic acid, 2,3-,2,4-, 2,5-, 2,6-, 3,4-or 3,5-diaminobenzenesulfonic acid,2-amino-1-phenol-4-sulfonic acid and6-amino-4-chloro-1-phenol-2-sulfonic acid. α-naphthylamine,β-naphthylamine, 1,5-diaminonaphthalene, 1-amino-5-hydroxynaphthalene,1,8-diaminonaphthalene, 2,3-diminonaphthalene, 4-amino-1-naphthol,1-amino-5-naphthol, 1,2-naphthylenediamine-7-carboxylic acid,1,5-naphthylenediamine-2-carboxylic acid,1,5-naphthylenediamine-4-carboxylic acid,1,6-naphthylenediamine-4-carboxylic acid,1,8-naphthylenediamine-4-carboxylic acid,1,2-naphthylenediamine-3-sulfonic acid,1,2-naphthylenediamine-4-sulfonic acid,1,2-naphthylenediamine-5-sulfonic acid,1,2-naphthylenediamine-6-sulfonic acid,1,2-naphthylenediamine-7-sulfonic acid,1,3-naphthylenediamine-5-sulfonic acid,1,3-naphthylenediamine-6-sulfonic acid,1,4-naphthylenediamine-2-sulfonic acid,1,4-naphthylenediamine-7-sulfonic acid,1,5-naphthylenediamine-2-sulfonic acid,1,5-naphthylenediamine-4-sulfonic acid,1,5-naphthylenediamine-7-sulfonic acid,1,6-naphthylenediamine-2-sulfonic acid,1,6-naphthylenediamine-4-sulfonic acid,1,6-naphthylenediamine-7-sulfonic acid,1,8-naphthylenediamine-4-sulfonic acid,1,8-naphthylenediamine-3,6-disulfonic acid,1,8-naphthylenediamine-4,5-disulfonic acid,α-amino-β-naphthalenepropionic acid, α-amino-β-naphthalenecarboxylicacid, 2-naphthylamine-1-sulfonic acid, 8-naphthylamine-1-sulfonic acid,5-naphthylamine-1-sulfonic acid, 1-amino-2-naphthol-4-sulfonic acid,2-amino-8-naphthol-6-sulfonic acid (γ-acid),2-amino-5-naphthol-7-sulfonic acid (J-acid) and1-amino-8-naphthol-3,6-disulfonic acid (H-acid), and diphenylamines,such as 4-aminodiphenylamine, 2-aminodiphenylamine,4,4′-diaminodiphenylamine, 4-hydroxydiphenylamine,4-amino-3′-methoxydiphenylamine, 4-amino-4′-hydroxydiphenylamine,4-carboxydiphenylamine, 4-amino-4′-carboxydiphenylamine,4-sulfodiphenylamine and 4-amino-4′-sulfodiphenylamine.

The aromatic hydroxyl compounds are exemplified by phenols andderivatives thereof, such as phenol, hydroquinone, resorcinol, catechol,hydroxyhydroquinone, pyrogallol, o-, m- or p-chlorophenol, o-, m- orp-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoicacid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid,3,5-dihydroxybenzoic acid and 2,5-, 2,6- or 3,5-dihydroxytoluene.

In addition, they are exemplified by naphthols and derivatives thereof,such as α-naphthol, β-naphthol, 1,3-, 1,4-, 1,5-, 2,3-, 2,6- or2,7-dihydroxynaphthalene, 1-hydroxy-2-naphthoic acid and3-hydroxy-2-naphthoic acid.

The self-condensation of a quinone compound or the condensation of aquinone compound with an aromatic hydroxyl compound and/or an aromaticamine compound is carried out in an organic solvent medium, optionallyin the presence of a condensation catalyst. The organic solvent mediumhas a pH within the range of from 1 to 13, preferably from 4 to 10, andpH adjusters may be used without any particular limitations. The pHadjusters used include acidic compounds, for example, phosphoric acid,sulfuric acid, phytic acid and acetic acid; and alkali compounds, forexample, alkaline metal compounds or ammonium compounds, such as LiOH,KOH, NaOH, Na₂CO₃, Na₂SiO₃, Na₂HPO₄ and NH₄OH; and organic aminecompounds, such as ethylenediamine, monoethanolamine andtriethanolamine.

As the medium for the condensation reaction, organic solvents asexemplified by alcohols, ketones and esters, or mixed solvents of waterand organic solvents miscible with water are preferred. Usable organicsolvents miscible with water include, for example, alcohols, such asmethanol, ethanol and propanol; ketones, such as acetone and methylethyl ketone; and esters, such as methyl acetate and ethyl acetate.

The condensation catalyst may be optionally used which is exemplified byazo catalysts such as α,α′-azobisisobutylonitrile andα,α′-azobis-2,4-dimethylvaleronitrile; elementary or molecular singlehalogens, such as iodine, bromine and chlorine; peroxides, such ashydrogen peroxide, sodium peroxide, benzoyl peroxide, potassiumpersulfate, ammonium persulfate, peracetic acid, cumene hydroperoxide,perbenzoic acid and p-menthane hydroperoxide; oxygen acids or oxygenacid salts, such as iodic acid, periodic acid, potassium periodate andsodium perchlorate. Incidentally, since the quinone compound acts as acondensation catalyst, the condensation reaction takes place even in theabsence of a condensation catalyst.

The condensation reaction may be generally carried out at roomtemperature to 200° C. for 0.5 to 100 hours.

When (a) a quinone compound and (b) an aromatic hydroxyl compound and/oran aromatic amine compound are condensed, the proportion of bothreactive components used depends on the types of the aromatic aminecompounds, quinone compounds and aromatic hydroxyl compounds, thereaction temperature and the reaction time. It is preferable to use from0.01 to 10.0 mols of the component (b) per mol of the component (a).

Sulfide Compounds of Aromatic Hydroxyl Compounds

Sulfide compounds of aromatic hydroxyl compounds refer to condensationproducts of aromatic hydroxyl compounds with sulfur chlorides such assulfur monochloride and sulfur dichloride. Use of such sulfide compoundsof aromatic hydroxyl compounds in the polymer scale preventive agent isdisclosed in, e.g., Japanese Pre-examination Patent Publication (kokai)Nos. 4-311702, 4-339801, 5-155905 and 6-9711.

The aromatic hydroxyl compounds may include aromatic hydroxyl compoundsof naphthol compounds described above, phenol compounds and the like.

To obtain the sulfide compounds, various methods are available. Forexample, a method is available in which the above phenols and sulfurchlorides such as sulfur monochloride and sulfur dichloride aresubjected to condensation reaction. This reaction is carried out in anorganic solvent inert to sulfur chlorides, in which a polyhydric phenolhas been dissolved. Such an organic solvent may include, e.g., aromatichydrocarbons such as toluene, xylene and chlorobenzene, and ethylenedichloride, chloroform and ethyl acetate. The phenol and the sulfurchloride may be in such a ratio that the latter is from about 0.5 to 2mols, and preferably from about 0.9 to 1.2 mols, per mole of the former.The reaction may be carried out at a temperature of from about 50° C. toabout 150° C. Hydrogen chloride formed as a by-product may bevolatilized, or, in a closed system, a dehydrochlorinating agent such astriethylene-amine may be used. After the reaction has been completed, inan instance where the reaction product stand dissolved in the solvent,the solvent may be removed by evaporation to take out the reactionproduct. In an instance where the reaction product stand deposited,solid-liquid separating operation such as filtration may be carried outto take out the reaction product.

As another method for obtaining the sulfide compound, a method isavailable in which a polyhydric phenol and a small amount of an alkalihydroxide are heated and melted, sulfur powder is added thereto littleby little and further the temperature is raised to about 150° C. toabout 200° C., where the reaction is carried out while releasing to theoutside of the system the hydrogen sulfide being formed, the reactionmixture is cooled and thereafter dissolved in the solvent describedlater, followed by filtration to collect the insoluble matter, which isthen neutralized with a dilute acid, and the aqueous phase is removed toobtain the compound in the form of a solution.

Heterocyclic compound having 5 or more conjugated π bonds:

The heterocyclic compounds having 5 or more conjugated π bonds include,for example, oxygen-containing heterocyclic compounds,nitrogen-containing heterocyclic compounds, sulfur-containingheterocyclic compounds, dicyclic compounds having a nitrogen atompossessed in common by the two rings, and alkaroids.

First, as the oxygen-containing heterocyclic compounds, there may beincluded:

benzofuran, isobenzofuran, dibenzofuran and derivatives thereof, such asfurano-[2′,3′-7,8]flavone, 9-phenylanthracene,o-hydroxymethyltriphenylcarbinol, 3,3′-diphenylphthalide, rubrene,α-sorinine and phenazone;

pyran derivatives and pyrone derivatives, such as2-p-hydroxyphenyl-4,6-diphenylpyrylium ferrichloride, anhydrobase,benzopyran and 6-phenylcoumarin;

chromenol derivatives and chromene derivatives, such as6-methyl-2,3-diphenylchromone,6-methyl-2,3-diphenyl-4-(p-tolyl)-1,4-benzopyran-4-ol, chromanol,γ-chromene, hydroxychmarone, chromene, cyanizine chloride, fisetin,chrysinidine, apigenidin and rotoflavinidine;

flavone, flavonol and isoflavon derivatives, such as flavonol, flavone,fukugetin;

coumarin, its derivatives, isocoumarin and its derivatives, such as7-hydroxy-3,4 -benzocoumarin, dicoumarol, angelicin, psoralen,bergapten, bergaptol, xanthotoxin, xanthotoxal, isopimpinellin,pimpinellin, oroselol, oroselone, peucedanin, hydroxypeucedanin,ostruthol, medakenine, nodakenetin, seselin, xanthyletin, xanthoxyletin;and

xanthone and related compounds; such as dixanthylene, 9-phenylxanthene,isoxanthone, 1,2,7,8-dibenzoxanthene, 3,9-diphenylxanthene,9,9-diphenylxanthene, and the like.

Next, the nitrogen-containing heterocyclic compounds may include:

indoles, such as indolo[3,2-c]quinoline, indolo[1,2-c]quinazoline,2-(1-naphthyl)-3-triphenylmethylindole,2-(2-naphthyl)-3-triphenylmethylindole, 3,3′-diindolyl and3,2′-diindolyl;

oxoderivatives of indole, such as 3-(4-ethoxy-1-naphthyl)hydroxyindoleand indophenine;

carbazoles, such as 1-phenyl-1,2,3-benzotriazole, 2,2′-diaminodiphenyl,1,1′-dicarbazole;

porphyrins, such as porphyrazine, magnesium octamethyltetraazaporphyrin,azadipyromethine, diazacoproporphyrin, porphine andmesotetraphenylporphyrin;

oxazoles, such as phenanthrooxazole;

thiazoles, such as α-naphthothiazole, β-naphthothiazole,naphtho[1,2]thiazole, 2-methyl[1,2]thiazole,2-phenylnaphtho[1,2]thiazole, 2-methylnaphtho[2,1]-thiazole,2-hydroxynaphtho[2,1]thiazole, 2-aminonaphtho[1,2]thiazole and2-mercaptonaphtho[2]-thiazole;

oxadiazoles, such as naphtho[1,2]furazane;

quinoline and related compounds, such as quinoline, quinaldine,quinaldine-N-oxide, ethylquinoline, 2-phenylquinoline,3-methylquinoline, 4-phenylquinoline, 6-methylquinoline and2,4-dimethylquinoline;

isoquinoline and related compounds, such as 1-methylisoquinoline,1-phenylisoquinoline, 4-phenylisoquinoline, 1,1′-biisoquinoline and5,5′-bulsoquinoline;

acridine and related compounds, such as acridine, 1-methylacridine,9-phenylacridine, 9-(3-pyridinyl)acridine, 2-acridinol,acridine-3,6-diol, 4-methoxyacridine, 9-phenoxyacridine,1-nitroacridine, 4-aminoacridine, 1-aminoacridine,9-phenylaminoacridine, 9-hydroxyacridine and3,6-diamino-4,5-dimethylacridine;

phenanthridines, such as 3,4-benzoquinoline, 6-methylphenanthridine,6-aminomethylphenanthridine and 6-phenylphenanthridine;

anthrazolines, such as pyrido[2,3-g]quinoline,2,7-diphenyl[2,3-g]quinoline, 2,8-diphenylpyrido[3,2-g]-quinoline;

phenanthroline and related compounds, such as 1,7-phenanthroline and1,10-phenanthroline;

pyridoindoles, such as 1,9-pyridoindole, 2,9-pyridoindole and4,9-pyridoindole;

naphthylidine and related compounds, such as 1,5-naphthylidine,1,7-naphthylidine, 1,8-naphthylidine, 3-amino-1,5-naphthylidine,2-amino-1,5-naphthylidine and 2-hydroxy-1,7-naphthylidlne;

oxazine and related compounds such as phenoxazinone and resazurin;

thiazine and related compounds, such as phenothiazine,nitrophenothiazine, 4-amino-4′-anilinodiphenyl disulfide,2-chloro-10-(3-dimethylaminopropyl)phenothiazine,10-[1-methyl-3-piperidylmethyl)phenothiazine and2-acetyl-10-(3-dimethylaminopropyl)phenothiazine;

pyridazine and related compounds, such as cinnoline, 3-methylcinnoline,4-chlorocinnoline, 3-bromocinnoline, 4-cinnolinol, 4-aminocinnoline,phthalazine, 4-ethyl-2-phenylphthalazinone and phthalazine thiol;

pyrirmidine and related compounds, such as sulfadiazine, sulfisomidine,pteridine, 2,4-pterine diol, 2-amino-6-methyl-4-pteridinol,xanthopterine, quinazoline, 2,4-dichloroquinazoline and2,3-diphenyl-4-quinazoline;

pyrazine related compounds, such as quinoxaline and 2-methylquinoxaline;

tri- and tetra-hetero six-membered cyclic compounds, such as1,2,4-benzotriazine and 1,2,4-benzotriazine-3-ol;

Further, the sulfur-containing heterocyclic compounds may include:

fused thiophene compounds, such as dihydronaphtho(2,1-b]-thianaphthene,1,3-diphenylisothianaphthene and dibenzothiophene;

five-membered monocyclic compounds containing 2 hetero atoms, such as3,4-dihydronaphtho-2,1-trithione, thiaflavone, thiacoumarln,thiaxanthene, thiaxanthohydrol, thiaxanthone, Milacil D, andbisthiaxanthylene;

six-membered cyclic compound having two or more hetero atoms, such asthianthrene, 2,7-dimethylthianthrene, 1-thianthrenyl lithium,1-chlorothianthrene and phenoxathine.

Further, other useful compounds may include:

dicyclic compounds having a nitrogen atom possessed in common by the tworings, such as 2:3-benzopyrrocoline,1,5,8-trimethyl-2:3-benzopyrrocoline and1-ethyl-5,8-dimethyl-2:3-benzopyrrocoline; and

alkaroids, such as casimiroin, 2-penthylquinoline,4-hydroxy-2-pentylquinoline and 4-methoxy-2-pentylquinoline.

Of the conjugated π bond compounds, it is preferable to use those whichare condensation products of aromatic compounds and have aweight-average molecular weight of 500 or more.

Of the condensation products of aromatic compounds, aldehydecompound/aromatic hydroxyl compound condensation products and quinonecompound condensation products are particularly preferred.

The first layer having been formed, may preferably have a surface havinga contact angle to water of 60° or more, and more preferably from 70 to130°, and still more preferably from 80 to 130° after the surface hasbeen brought into contact with a solution of mixture of water and avinyl chloride monomer in a weight ratio of 1:1, at 50° C. for 1 hour.Accordingly, it is preferable to use a first coating liquid that canform such a first layer. Selection of a conjugated π bond compoundcapable of forming a first layer having a contact angle to water of 60°or more, can be readily performed by way of a simple test.

Making this layer have a contact angle to water of 60° or above can beeffective for forming a first layer having a high adhesion to inner wallsurfaces, which are constituted of a metal such as stainless steel, orglass, of the polymerization vessel and having a durability. If thiscontact angle is too small, the first layer may have so weak an adhesionto the inner wall surfaces and others that the resultant coating filmtends to be washed off with the water formed upon condensation of thesteam. Thus, any uniform first layer with a good adhesion cannot beformed.

The first coating liquid for formation of the first layer is prepared bydissolving the conjugated π bond compound in a proper solvent. Thesolvent includes, for example, water; alcohol solvents, such asmethanol, ethanol, propanol, butanol, 2-butanol, 2-methyl-1-propanol,2-methyl-2-propanol, 3-methyl-1-butanol, 2-methyl-2-butanol and2-pentanol; ketone solvents, such as acetone, methyl ethyl ketone andmethyl isobutyl ketone; ester solvents, such as methyl formate, ethylformate, methyl acetate, ethyl acetate and methyl acetoacetate; ethersolvents, such as 4-methyldioxolane and ethylene glycol diethyl ether;furans; and non-protonic solvents, such as dimethylformamide, dimethylsulfoxide and acetonitrile. The solvents may be appropriately usedsingly or as a mixed solvent of two or more thereof.

Among the above solvents, preferred are water and a mixed solvent ofwater and an organic solvent miscible with water. Among the aboveorganic solvents, organic solvents miscible with water include alcoholsolvents, such as methanol, ethanol and propanol; ketone solvents, suchas acetone and methyl ethyl ketone; and ester solvents, such as methylacetate and ethyl acetate. Particularly, it is preferred that alcoholsolvents are used. In the case where a mixed solvent of water and anorganic solvent miscible with water is used, the organic solvent ispreferably contained in such an amount that there is no danger ofinflammation, evaporation and the like and there is no problem on safetyin handling, for example, on toxicity. Specifically, the amount ispreferably 50% by weight or less, more preferably 30% by weight or less.

The pH of the first coating liquid is selected appropriately dependingon the kind of the conjugated π bond compound. For example, forpyrogallol/acetone condensation products, polyhydric phenolself-condensation products and polyhydric naphthol self-condensationproducts, a pH of 2.0 to 6.5 is preferred. For this pH adjusters usedfor adjustment of the pH include, for example, hydrochloric acid,sufuric acid, phosphoric acid, pyrophosphoric acid and nitric acid. Forthe condensation products of aldehyde compound/aromatic hydroxylcompound, condensation products of an aromatic amine compound, andcondensation products of a quinone compound, a pH of 7.5 to 13.5 ispreferred, and a pH of 8.0 to 12.5 is more preferred. For that case,alkaline compounds used for pH adjustment include, for example, alkalimetal compounds or ammonium compounds, such as LiOH, NaOH, KOH, Na₂CO₃,Na₂HPO₄ and NH₄OH; andorganic amine compounds, such as ethylenediamine,monoethanolamine, diethanolamine and triethanolamine.

The conjugated π bond compound in the first coating liquid maypreferably be in a concentration ranging from 1.0 to 25.0% by weight,more preferably from 2.5 to 15.0% by weight, and still more preferablyfrom 4 to 10% by weight. If they are in too low a concentration, adifficulty may occur such that the steam must be used in a largequantity in order to form the first layer in an effective quantity. Ifthey are in too high a concentration, the coating liquid may becomeunstable to cause a precipitate during storage in a storage tank, or thefirst layer obtained by coating on the inner wall surfaces and othersmay have an uneven coating thickness to cause a decease in the scaleprevention effect. Preferably, all of the solutes are completelydissolved in a solvent to form the first coating liquid in a uniformsolution.

The first coating liquid may optionally contain a water-solublepolymeric compound, an inorganic colloid, etc. to such an extent thatthe performance of forming uniform coating films and the adhesion of thefirst layer to the inner wall surface, are not impaired, in addition tothe conjugated π bond compound.

[Coating-Film Second Layer]

The second layer is formed on the first layer thus formed. This secondlayer contains a dye and/or a pigment and a surface having a contactangle to water of less than 60°, and preferably from 10 to 55°, afterits surface has been brought into contact with a solution of mixture ofwater and a vinyl chloride monomer in a weight ratio of 1:1, at 50° C.for 1 hour. When this contact angle to water is less than 60°, thesecond layer exhibits a good effect of adhesion to the first layer.Simultaneously, monomers and polymers contained in the polymerizationreaction mixture can be prevented from adhering to the polymerizationvessel inner wall surfaces and others during polymerization, making itpossible to attain the scale prevention effect. If on the other hand thecontact angle to water is 60° or more, the monomers and polymers tendsto be absorbed on the coating film, making it impossible to attain asufficient scale prevention effect.

As the dye and pigment, there may be included, for example, azo dyes andpigments such as monoazo and polyazo dyes and pigments, metal complexazo dyes and pigments, stilbene azodyes and thiazol azo dyes;anthraquinone dyes and pigments such as anthraquinone derivatives,anthrone derivatives, and the like; indigoid dyes and pigments such asindigo derivatives, thioindigo derivatives, and the like; phthalocyaninedyes and pigments; carbonium dyes and pigments such as diphenylmethanedyes, triphenylmethane dyes and pigments, xanthene dyes and acridinedyes; quinoneimine dyes such as azine dyes, oxazine dyes and thiazinedyes; methine dyes such as polymethine or xyanine dyes; quinoline dyes;nitro dyes; benzoquinone and naphthoquinone dyes; naphthalimide dyes andpigments; perinone dyes; sulfide dyes; fluorescent dyes; azoic dyes; andreactive dyes. These may be used singly or in combination of two or morekinds. Typical examples of these dyes and pigments are enumerated belowmore specifically.

Azo dyes and pigments include the following compounds.

As the monoazo and polyazo dyes, there may be included, for example,C.I. Basic Yellow 32, 34 and 36; C.I. Basic Orange 2, 32, 33 and 34;C.I. Basic Red 17, 18, 22, 23, 24, 32, 34, 38, 39 and 40; C.I. BasicViolet 26 and 28; C.I. Basic Blue 58, 59, 64, 65, 66, 67 and 68; C.I.Basic Brown 1, 4, 11 and 12; C.I. Basic Black 8; C.I. Azoic DiazoComponent 4, 21, 27 and 38; C.I. Disperse Yellow 3, 4, 5, 7, 8, 23, 50,60, 64, 66, 71, 72, 76, 78 and 79; C.I. Disperse Orange 1, 3, 5, 13, 20,21, 30, 32, 41, 43, 45, 46, 49, 50 and 51; C.I. Disperse Red 1, 5, 7,12, 13, 17, 43, 52, 54, 56, 58, 60, 72, 73, 74, 75, 76, 80, 82, 84, 88,90, 97, 99, 101, 103, 113, 117, 122, 125, 126, 128 and 129; C.I.Disperse Violet 10, 24, 33, 38, 41, 43 and 96; C.I. Disperse Blue 85,92, 94 and 100; C.I. Disperse Brown 3 and 5; C.I. Disperse Black 1, 2,10, 26, 27, 28, 29, 30 and 31; C.I. Solvent Yellow 2, 6, 14, 15, 16, 19,21 and 56; C.I. Solvent Orange 1, 2, 5, 6, 14 and 45; C.I. Solvent Red1, 3, 23, 24, 25, 27 and 30; C.I. Solvent Brown 3, 5 and 20; C.I.Solvent Black 3; C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12,13, 14, 15, 16, 17, 23, 65, 73 and 83; C.I. Pigment Orange 1, 2, 5, 13,14, 15, 16, 17, 24 and 31; C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9,10 ,11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38,39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 112,114 and 163; C.I. Pigment Blue 25; C.I. Pigment Green 10; C.I. PigmentBrown 1 and 2; C.I. Pigment Black 1; C.I. Direct Yellow 1, 8, 11, 12,24, 26, 27, 28, 33, 44, 50, 58, 85, 86, 87, 88, 89, 98, 100 and 110;C.I. Direct Orange 1, 6, 8, 10, 26, 29, 39, 41, 49, 51, 57, 102 and 107;C.I. Direct Red 1, 2, 4, 13, 17, 20, 23, 24, 28, 31, 33, 37, 39, 44, 46,62, 63, 75, 79, 80, 81, 83, 84, 89, 95, 99, 113, 197, 201, 218, 220,224, 225, 226, 227, 228, 229, 230 and 231; C.I. Direct Violet 1, 7, 9,12, 22, 35, 51, 63, 90, 94 and 98; C.I. Direct Blue 1, 2, 6, 8, 15, 22,25, 71, 76, 77, 78, 80, 120, 123, 158, 160, 163, 165, 168, 192, 193,194, 195, 196, 203, 207, 225, 236, 237, 246, 248 and 249; C.I. DirectGreen 1, 6, 8, 28, 30, 31, 33, 37, 59, 63, 64 and 74; C.I. Direct Brown1A, 2, 6, 25, 27, 44, 58, 59, 101, 106, 173, 194, 195, 209, 210 and 211;C.I. Direct Black 17, 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 94, 105,106, 107, 108, 112, 113, 117, 118, 132, 133 and 146; C.I. Acid Yellow11, 17, 19, 23, 25, 29, 36, 38, 40, 42, 44, 49, 61, 70, 72, 75, 76, 78,79, 110, 127, 131, 135, 141, 142, 164 and 165; C.I. Acid Orange 1, 7, 8,10, 19, 20, 24, 28, 33, 41, 43, 45, 51, 56, 63, 64, 65, 67 and 95; C.I.Acid Red 1, 6, 8, 9, 13, 14, 18, 26, 27, 32, 35, 37, 42, 57, 75, 77, 85,88, 89, 97, 106, 111, 114, 115, 117, 118, 119, 129, 130, 131, 133, 134,138, 143, 145, 154, 155, 158, 168, 249, 252, 254, 257, 262, 265, 266,274, 276, 282, 283 and 303; C.I. Acid Violet 7, 11, 97 and 106; C.I.Acid Blue 29, 60, 92, 113, 117 and 120; C.I. Acid Green 19, 20 and48;C.I. Acid Brown 2, 4, 13, 14, 20, 53, 92, 100, 101, 236, 247, 266, 268,276, 277, 282, 289, 301 and 302; C.I. Acid Black 1, 7, 24, 26, 29, 31,44, 76, 77, 94, 109 and 110; C.I. Mordant Yellow 1, 3, 5, 23, 26, 30, 38and 59; C.I. Mordant Orange 1, 4, 5, 6, 8, 29 and 37; C.I. Mordant Red7, 9, 17, 19, 21, 26, 30, 63 and 89; C.I. Mordant Violet 5 and 44; C.I.Mordant Blue 7, 13, 44, 75 and 76; C.I. Mordant Green 11, 15, 17 and 47;C.I. Mordant Brown 1, 14, 15, 19, 21, 33, 38, 40, 52 and 87; C.I.Mordant Black 1, 3, 7, 9, 11, 17, 26, 32, 38, 43, 44, 51, 54, 65, 75,77, 84, 85, 86 and 87; C.I. Food Yellow 3 and 4; C.I. Food Red 7 and 9;

as the metal complex azo dyes, there may be included, for example, C.I.Solvent Yellow 61 and 80; C.I. Solvent Orange 37, 40 and 44; C.I.Solvent Red 8, 21, 83, 84, 100, 109 and 121; C.I. Solvent Brown 37; C.I.Solvent Black 23; C.I. Acid Black 51, 52, 58, 60, 62, 63, 64, 67, 72,107, 108, 112, 115, 118, 119, 121, 122, 123, 131, 132, 139, 140, 155,156, 157, 158, 159 and 191; C.I. Acid Yellow 59, 98, 99, 111, 112, 114,116, 118, 119, 128, 161, 162 and 163; C.I. Acid Orange 74, 80, 82, 85,86, 87, 88, 122, 123 and 124; C.I. Acid Red 180, 183, 184, 186, 194,198, 199, 209, 211, 215, 216, 217, 219, 256, 317, 318, 320, 321 and 322;C.I. Acid Violet 75 and 78; C.I. Acid Blue 151, 154, 158, 161, 166, 167,168, 170, 171, 175, 184, 187, 192, 199, 229, 234 and 236; C.I. AcidGreen 7, 12, 35, 43, 56, 57, 60, 61, 65, 73, 75, 76, 78 and 79; C.I.Acid Brown 19, 28, 30, 31, 39, 44, 45, 46, 48, 224, 225, 226, 231, 256,257, 294, 295, 296, 297, 299 and 300; C.I. Direct Yellow 39; C.I. DirectViolet 47 and 48; C.I. Direct Blue 90, 98, 200, 201, 202 and 226; C.I.Direct Brown 95, 100, 112 and 170;

as the stilbene azo dyes, there may be included, for example, C.I.Direct Black 62; and

as the thiazole azo dyes, there may be included, for example, C.I.Direct Red 9 and 11.

The anthraquinone dyes and pigments include the following compounds.

As the anthraquinone derivatives, there may be included, for example,C.I. Basic Violet 25; C.I. Basic Blue 21, 22, 44, 45, 47, 54 and 60;C.I. Azoic Diazo Component 36; C.I. Vat Yellow 2, 3, 10, 20, 22 and 33;C.I. Vat Orange 13 and 15; C.I. Vat Red 10, 13, 16, 31, 35 and 52; C.I.Vat Violet 13 and 21; C.I. Vat Blue 4, 6, 8, 12, 14, 64, 66, 67 and 72;C.I. Vat Green 8, 13, 43, 44 and 45; C.I. Vat Brown 1, 3, 22, 25, 39,41, 44, 46, 57, 68, 72 and 73; C.I. Vat Black 8, 14, 20, 25, 27, 36, 56,59 and 60; C.I. Disperse Orange 11; C.I. Disperse Red 4, 9, 11, 15, 53,55, 65, 91, 92, 100, 104, 116 and 127; C.I. Disperse Violet 1, 4, 8, 23,26, 28, 30 and 37; C.I. Disperse Blue 1, 3, 5, 6, 7, 20, 26, 27, 54, 55,56, 60, 61, 62, 64, 72, 73, 75, 79, 81, 87, 90, 91, 97, 98, 99, 103, 104and 105; C.I. Disperse Yellow 51; C.I. Solvent Violet 13 and 14; C.I.Solvent Blue 11, 12, 35 and 36; C.I. Solvent Green 3; C.I. Pigment Red83 and 89; C.I. Pigment Blue 22; C.I. Acid Violet 31, 34, 35, 41, 43,47, 48, 51, 54, 66 and 68; C.I. Acid Blue 23, 25, 27, 40, 41, 43, 45,54, 62, 72, 78, 80, 82, 112, 126, 127, 129, 130, 131, 138, 140, 142,143, 182, 183, 203, 204 and 205; C.I. Acid Green 25, 27, 28, 36, 40, 41and 44; C.I. Acid Brown 27; C.I. Acid Brown 48 and 50; C.I. Mordant Red3 and 11; C.I. Mordant Blue 8 and 48; C.I. Mordant Black 13; C.I.Pigment Violet 5; and

as anthrone derivatives, there may be included, for example, C.I. VatYellow 1 and 4; C.I. Vat Orange 1, 2, 3, 4 and 9; C.I. Vat Violet 1, 9and 10; C.I. Vat Blue 18, 19 and 20; C.I. Vat Green 1, 2, 3 and 9; C.I.Vat Black 9, 13, 19 and 57; C.I. Vat Red 13; C.I. Acid Red 80, 82 and83.

Indigoid dyes and pigments Include the following compounds.

As the indigo derivatives, there may be included, for example, C.I. VatBlue 1, 3, 5, 35 and 41; C.I. Reduced Vat Blue 1; C.I. Pigment Violet 19and 122; C.I. Acid Blue 74 and 102; C.I. Solubilized Vat Blue 5 and 41;C.I. Solubilized Vat Black 1; C.I. Food Blue 1; and

as thioindigo derivatives, there may be included, for example, C.I. VatOrange 5; C.I. Vat Red 1, 2 and 61; C.I. Vat Violet 2 and 3; C.I.Pigment Red 87 and 88; C.I. Vat Brown 3.

As phthalocyanine dyes and pigments, there may be included, for example,C.I. Solvent Blue 55; C.I. Pigment Blue 15, 16 and 17; C.I. PigmentGreen 36, 37 and 38; C.I. Direct Blue 86 and 199; C.I. Mordant Blue 58.

The carbonium dyes and pigments include the following compounds.

As diphenylmethane dyes, there may be included, for example, C.I. BasicYellow 2;

as triphenylmethane dyes, there may be included, for example, C.I. BasicRed 9; C.I. Basic Violet 1, 3 and 14; C.I. Basic Blue 1, 5, 7. 19, 26,28, 29, 40 and 41; C.I. Basic Green 1 and 4; C.I. Solvent Violet 8; C.I.Solvent Blue 2 and 73; C.I. Pigment Violet 3; C.I. Pigment Blue 1, 2 and3; C.I. Pigment Green 1, 2 and 7; C.I. Direct Blue 41; C.I. Acid Violet15 and 49; C.I. Acid Blue 1, 7, 9, 15, 22, 83, 90, 93, 100, 103 and 104;C.I. Acid Green 3,9 and 16; C.I. Mordant Violet 1; C.I. Mordant Blue 1,29 and 47; C.I. Food Violet 2; C.I. Food Blue 2; C.I. Food Green 2;

as xanthene dyes, there may be included, for example, C.I. Basic Red 1;C.I. Solvent Red 49; C.I. Pigment Red 81 and 90; C.I. Pigment Violet 1,2 and 23; C.I. Acid Red 51, 52, 87, 92 and 94; C.I. Mordant Red 15 and27; C.I. Food Red 14; and

as acridine dyes, there may be included, for example, C.I. Basic Orange14 and 15.

Quinoneinmine dyes include the following compounds.

As azine dyes, there may be included, for example, C.I. Basic Red 2;C.I. Basic Black2; C.I. Solvent Black 5 and7; C.I. Acid Blue 59; C.I.Acid Black 2;

as oxazine dyes, there may be included, for example, C.I. Basic Blue 3;C.I. Direct Blue 106 and 108; and

as thiazine dyes, there may be included, for example, C.I. Basic Yellow1; C.I. Basic Blue 9, 24 and 25.

Methine dyes include the following compounds.

As polymethine or cyanine dyes, there may be included, for example, C.I.Basic Yellow 11, 13, 14, 19, 21, 25, 28, 33 and 35; C.I. Basic Orange 21and 22; C.I. Basic Red 12, 13, 14, 15, 27, 29, 35, 36 and 37; and C.I.Basic Violet 7, 15, 21 and 27.

As quinoline dyes, there may be included, for example, C.I. Basic Green6; C.I. Disperse Yellow 54 and 56; C.I. Solvent Yellow 33; and C.I. AcidYellow 3.

As nitro dyes, there may be included, for example, C.I. Disperse Yellow1, 33, 39, 42, 49 and 54; C.I. Acid Yellow 1.

As benzoquinone and naphthoquinone dyes, there may be included, forexample, C.I. Disperse Blue 58 and 108; and C.I. Acid Brown 103, 104,106, 160, 161, 165 and 188.

As naphthalimide dyes and pigments, there may be included, for example,C.I. Pigment Red 123; C.I. Vat Violet 23 and 29; and C.I. Acid Yellow 7.

As perinone dyes, there may be included, for example, C.I. Vat Orange 7and 15.

As sulfide dyes, there may be included, for example, C.I. SolubilizedSulfer Yellow 2; C.I. Sulfer Yellow 4; C.I. Sulfer Orange 3; C.I. SulferRed 2, 3, 5 and 7; C.I. Solubilized Sulfer Blue 15; C.I. Sulfer Blue 2,3, 4, 6, 7, 9 and 13; C.I. Sulfer Green 2, 3, 6, 14 and 27; C.I.Solubilized Sulfer Brown 1 and 51; C.I. Sulfer Brown 7, 12, 15 and 31;C.I. Sulfer Black 1, 2, 5, 6, 10, 11 and 15; C.I. Vat Yellow 35, 42 and43; and C.I. Vat Blue 43 and 56.

As fluorescent dyes, there may be included, for example, FluorescentBrightening Agent 14, 22, 24, 30, 32, 37, 45, 52, 54, 55, 56, 84, 85,86, 87, 90, 91, 104, 112, 121, 134, 135, 153, 162, 163, 164, 166, 167,168, 169, 170, 171, 172, 173, 174, 175, 176 and 177.

As azoic dyes, there may be included, for example, C.I. Azoic DiazoComponent 17, 20, 22, 24, 26, 31, 35, 41, 47, 48, 109 and 121; C.I.Azoic Coupling Component 2, 3, 4, 5, 7, 8, 10, 11, 12, 14, 15, 16, 17,18, 19, 20, 23, 26, 28, 29, 35, 36, 37, 41 and 108; C.I. Azoic Brown 2,7, 11 and 15; C.I. Azoic Black 1 and 5; C.I. Azoic Yellow 1 and 2; C.I.Azoic Orange 2, 3 and 7; C.I. Azoic Red 1, 2, 6, 9, 16 and 24; C.I.Azoic Violet 1, 2, 6, 7, 9 and 10; and C.I. Azoic Green 1.

As reactive dyes, there may be included, for example, C.I. ReactiveYellow 1, 2, 3, 4, 6, 7, 11, 12, 13, 14, 15, 16, 17, 18, 22, 23, 24, 25,26, 27, 37 and 42; C.I. Reactive Orange 1, 2, 4, 5, 7, 13, 14, 15, 16,18, 20, 23 and 24; C.I. Reactive Red 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 13,15, 16, 17, 19, 20, 21, 22, 23, 24, 28, 29, 31, 32, 33, 34, 35, 36, 37,38, 39, 40, 41, 42, 43, 45, 46, 49, 50, 58, 59, 63 and 64; C.I. ReactiveViolet 1, 2, 4, 5, 8, 9 and 10; C.I. Reactive Blue 1, 2, 3, 4, 5, 7, 8,9, 13, 14, 15, 17, 18, 19, 20, 21, 25, 26, 27, 28, 29, 31, 32, 33, 34,37, 38, 39, 40, 41, 43, 44 and 46; C.I. Reactive Green 5, 6, 7 and 8;C.I. Reactive Brown 1, 2, 5, 7, 8, 9, 10, 11, 14 and 16; and C.I.Reactive Black 1, 3, 4, 5, 6, 8, 9, 10, 12, 13, 14 and 18.

Further, pigments maybe exemplified by inorganic pigments such as ChromeYellow, Zinc Yellow, ZTO type zinc chromate, red lead, iron oxidepowder, zinc white, aluminum powder and zinc powder.

Of these dyes and pigments, preferred are azo dyes and pigments,anthraquinone dyes and pigments, indigoid dyes and pigments,quinoneimine dyes and naphthoquinone dyes, among which particularlypreferred are acid dyes, direct dyes and basic dyes. A surface having acontact angle to water of less than 60° after coating can be easilycontrolled by using these dyes.

The second coating liquid for the second layer is prepared by dissolvingor dispersing at least one compound selected from the above dyes andpigments in a suitable solvent. As the solvent, water or a mixed solventof water and a hydrophilic organic solvent having an affinity for watermay be used. Of the above solvents, the hydrophilic organic solvent mayinclude alcohol solvents such as methanol, ethanol and propanol; ketonetype solvents such as acetone and methyl ethyl ketone; and ester typesolvents such as methyl acetate and ethyl acetate. In addition, of theabove solvents, it is preferable to use alcohol type solvents. In thecase when the mixed solvent of water and the hydrophilic organic solventis used, the hydrophilic organic solvent may preferably be used in sucha content that there is no danger of combustion or explosion and thereis no problem on the safety in handling such as toxicity. Statedspecifically, the hydrophilic organic solvent may preferably be in acontent of 50% by weight or less, and more preferably 30% by weight orless.

The pH of the second coating liquid is preferably 6 or less, morepreferably 0.5 to 4. A pH adjuster of an acid such as sulfuric acid,phosphoric acid, phytic acid and tannic acid may also optionally beused. In addition, it is preferable to add an inorganic colloid such ascolloidal silica or a water-soluble polymeric compound such as polyvinylalcohol and polyvinyl pyrrolidone. Preferably, the solutes arecompletely dissolved to form the second coating liquid in a uniformsolution.

The dyes and/or pigments in the second coating liquid may preferably bein a concentration ranging from 0.01 to 20% by weight, more preferablyfrom 0.1 to 15% by weight.

[Carrier Steam]

According to the process of the present invention, both the first layerand the second layer are formed by coating the respective coatingliquids by means of steam as a carrier. The steam used may be steamusually available or superheated steam, and may preferably be steamhaving a pressure of from 2 to 35 kgf/cm²·G. and more preferably onehaving a pressure of from 2.8 to 20 kgf/cm²·G.

The steam may preferably have a temperature of from 120 to 260° C., andmore preferably form 130 to 200° C.

The pressure and temperature of the steam described above are the valuesmeasured before mixing of the steam with a coating liquid, for example,at the inside of the steam feed line 6 as shown in FIG. 1 describedbelow.

[Formation of Coating Film]

The coating film comprising the first layer and the second layer will bedescribed with reference to a coating apparatus in FIG. 1, whichillustrates the arrangement in a polymerization apparatus.

Step 1. (Pre-heating of polymerization vessel inner wall surfaces andothers by steam)

Hot water or the like is passed through a jacket 2 attached to apolymerization vessel 1 to pre-heat the polymerization vessel inner wallsurfaces to a temperature of 50° C. or above (preferably from 50 to 95°C.). At the upper part of this polymerization vessel, a coating ring 4is provided which is formed of a ring-shaped pipe and has upward nozzles3 b and downward nozzles 3 a. To the coating ring 4, a line 5 isconnected through which the steam and the coating liquid are fed fromthe outside of the polymerization vessel 1. To line 5 are connected asteam feed line 6, the first coating liquid feed line 7 and the secondcoating liquid feed line 8 through the respective valves. If necessary,the steam (usual steam or superheated steam) may be blown into thevessel from the coating nozzles 3 a and 3 b of this coating ring 4 topre-heat also baffles (not shown) and stirring blades (not shown). Inthis apparatus, the steam is fed to the coating ring 4 from a steamfeeder 9 via a flowmeter 10 through lines 6 and 5.

Step 2. (First-stage coating)

The steam is fed to the coating ring 4, and the first coating liquidheld in a first coating liquid tank 11 is fed to the coating ring 4through lines 7 and 5 by means of a pump 12 or an aspirator valve(notshown). P denotes a pressure gauge. The first coating liquid iscarried by the steam and is, in the state of mist, applied to and coatedon polymerization vessel inner wall surfaces and surfaces with whichpolymers come into contact during polymerization, such as bafflesurfaces and stirring blade surfaces. Simultaneously with this coating,the first coating liquid coated on these surfaces is dried (simultaneousdrying), so that the first layer is formed. Hence, it is unnecessary tomake any particular operation for the drying.

The steam (G) and the coating liquid (L) may preferably be in a mixingratio (L/G) of from 0.005 to 0.8, and more preferably from 0.01 to 0.2,as flow rate ratio on the basis of weight.

Step 3. (Second-stage coating)

Subsequently, in the state the steam is kept flowing, the second coatingliquid held in a second coating liquid tank 13 is fed to the coatingring 4 similarly through lines 8 and 5 by means of a pump 14, and iscoated to form the second layer (not shown). Like the instance of thefirst-stage coating, the second coating liquid coated on the first layeris dried simultaneously with the coating (simultaneous drying), so thatthe second layer is formed, thus it is unnecessary to make anyparticular drying operation.

Also in this second-stage coating, the steam(G) and the coating liquid(L) may preferably be in a mixing ratio(L/G) of 0.005 to 0.8, morepreferably 0.01 to 0.2. in terms of flow rate ratio on the basis ofweight.

Step 4. (Water washing)

After the feeding of the steam and the coating liquid are stopped, theinside of the polymerization vessel is washed with cleaning water heldin a water tank 15. The cleaning water is fed into the polymerizationvessel 1 from nozzles 18 through a line 17 by means of a pump 16.However, water washing is unnecessary if the coating liquid does not soaffect the product quality.

The first layer thus formed may preferably have a dried coating weightof from 0.0005 to 3 g/m², and more preferably from 0.0005 to 1 g/m². Thesecond layer may preferably have a dried coating weight of from 0.0005to 2 g/m², and more preferably from 0.0005 to 1 g/m². The first layerand second layer may preferably have a total dried coating weight offrom 0.001 to 5 g/m², and more preferably from 0.001 to 2 g/m².

Polymerization

The process of the present invention is applied to the polymerization ofa monomer having an ethylenically unsaturated double bond. Examples ofthe monomer include vinyl halides such as vinyl chloride; vinyl esterssuch as vinyl acetate and vinyl propionate; acrylic acid, methacrylicacid and their esters or salts; maleic acid, fumaric acid and theiresters or anhydrides; diene monomers such as butadiene, chloroprene andisoprene; styrene; acrylonitrile; vinylidene halides; and vinyl ether.Examples particularly suitable for practicing the process of the presentinvention include the production of polymers of vinyl halides, such asvinyl chloride, vinylidene halides, or a monomeric mixture comprisedprimarily of them by suspension polymerization or emulsionpolymerization in an aqueous medium. The coating film formed by theprocess of the present invention has a high durability even formonomers, such as α-methylstyrene, acrylic acid esters, acrylonitrileand vinyl acetate, which have a high solvency power for the conventionalcoating film, so that the process can be carried out suitably even forthe production of polymer beads and latex comprised of polystyrene,polymethacrylate, polyacrylonitrile, etc.; the production of syntheticrubbers such as SBR, NBR, CR, IR, IIR, etc.(these synthetic rubbers aregenerally produced by emulsion polymerization); and the production ofABS resin.

In the polymerization of one or more of these monomers, an object ofpreventing scale can be effectively accomplished irrespective ofpolymerization types, such as suspension polymerization, emulsionpolymerization, bulk polymerization and solution polymerization, even inthe presence of any of additives such as emulsifiers, stabilizers,lubricants, plasticizers, pH adjusters and chain transfer agents. Forexample, in the case of suspension polymerization or emulsionpolymerization of a vinyl monomer, various additives are optionallyadded, as required. The additives include, for example, suspendingagents such as partially saponified polyvinyl alcohol and methylcellulose; anionic emulsifiers such as sodium lauryl sulfate; nonionicemulsifiers such as sorbitan monolaurate and polyoxyethylene alkylether; stabilizers such as tribasic lead sulfate, calcium stearate,dibutyltin dilaurate and dioctyltin mercaptide; chain transfer agentssuch as trichloroethylene and mercaptans; and pH adjusters. According tothe present process, deposition of scale is effectively prevented in thepresence of any of the additives above.

The remarkable polymer scale deposition preventive effect of theinvention is exhibited without being affected by the kind ofpolymerization catalysts even when any of catalysts is used.Specifically, the catalysts include, for example, t-butylperoxyneodecanoate, bis(2-ethylhexyl)peroxydicarbonate,3,5,5-trimethylhexanoyl peroxide, α-cumyl peroxyneodecanoate, cumenehydroperoxide, cyclohexanone peroxide, t-butyl peroxypivarate,bis(2-ethoxyethyl)peroxydicarbonate, benzoyl peroxide,diisopropylbenzene hydroperoxide, lauroyl peroxide, 2,4-dichlorobenzoylperoxide, diisopropyl peroxydicarbonate, α,α′-azobisisobutylonitrile,α,α′-azobis-2,4-dimethylvaleronitrile, di-2-ethylhexyldiperoxyisophthalate, potassium persulfate and ammonium persulfate.

Other conditions for polymerization may be those which areconventionally used, and there are no limitations unless the effects ofthe present invention are impaired.

In the following, taking the cases of suspension polymerization,solution polymerization and bulk polymerization as examples, typicalconditions of polymerization will be described.

First, in the suspension polymerization, water and a dispersant arecharged into a polymerization vessel, and then a polymerizationinitiator is charged therein. Subsequently, the polymerization vessel isevacuated to reduce the initial pressure to a value of 0.1 to 760 mmHg(0.01 to 101 kPa), and a monomer or monomers are then charged, whereuponthe internal pressure takes usually a value of 0.5 to 30 kgf/cm²·G (150to 3,040 kPa). Thereafter, polymerization is carried out at a reactiontemperature of 30 to 150° C. During the polymerization, one or morematerials selected from water, a dispersant and a polymerizationinitiator are, optionally, added. Reaction temperature during thepolymerization is different depending on the kind of a monomer to bepolymerized. For example, in the case of polymerizing vinyl chloride,polymerization is carried out at 30 to 80° C., while in the case ofpolymerizing styrene, polymerization is carried out at 50 to 150° C. Thepolymerization may be judged to be completed when the pressure insidethe polymerization vessel has dropped to a value of 0 to 7 kgf/cm²·G(100 to 790 kPa) or when there has been observed substantially nodifference between the inlet temperature and outlet temperature of acooling water flowing into and out of a jacket providedcircumferentially of the polymerization vessel (i.e., when liberation ofheat due to the polymerization reaction has subsided). The amounts ofthe water, dispersant and polymerization initiator are generally 20 to500 parts by weight, 0.01 to 30 parts by weight, and 0.01 to 5 parts byweight, respectively, per 100 parts by weight of the monomer.

In solution polymerization, an organic solvent, such as toluene, xyleneand pyridine, is used as the polymerization medium, in place of water.If necessary, a dispersant may be used. The other conditions forpolymerization are generally the same as those described for suspensionpolymerization.

In bulk polymerization, after a polymerization vessel is evacuated to apressure of about 0.01 to 760 mmHg (0.001 to 101 kPa), a monomer and apolymerization initiator are charged into the polymerization vessel, andthen polymerization is carried out at a reaction temperature of −10 to250° C. For example, the reaction temperature is 30 to 80° C. for thepolymerization of vinyl chloride, and is 50 to 150° C. for thepolymerization of styrene.

EXAMPLES

The present invention will now be described below in greater detail bygiving Examples. In the following, “part (s)” refers to “part(s) byweight”. In tables, “auxiliary agent” refers to “polymer scalepreventive auxiliary agent”.

Production of Condensation Products

In the following Production Examples, the weight-average molecularweight of each condensation product obtained was measured in thefollowing way.

Measurement of weight-average molecular weight

Weight-average molecular weight in terms of polystyrene was measured bygel permeation chromatography (GPC) under the following measurementconditions.

Columns:

Guard column:

Tradename: shim-pack GPC-800DP, manufactured by

Shimadzu Corporation.

Analytical columns:

Tradename: shim-pack GPC-803D, 802D, manufactured by ShimadzuCorporation.

Mobile phase: 10 mM LiBr/DMF

Flow rate: 1.0 ml/min

Detector: RI

Temperature: 60° C.

Production Example 1

Production of Condensation Product No. 1:

Into a pressure-resistant reaction vessel, 30,000 mols (960 kg) ofmethanol, 100 mols (15.8 kg) of 1,8-diaminonaphthalene, 50 mols (5.4 kg)of p-benzoquinone and 250 mols (31.5 kg) of pyrogallol were charged, andthe temperature was raised to 70° C. with stirring. After the reactionwas carried out at 70° C. for 10 hours, the reaction mixture was cooledto obtain a methanol solution of a condensation product (CondensationProduct No. 1). The Condensation Product No. 1 had a weight-averagemolecular weight of 3,500.

Production Example 2

Production of Condensation Product No. 2:

With reference to Production Example 3 disclosed in Japanese PatentPublication (kokoku) No. 6-62709, a scale deposition preventive agentwas produced.

Into a pressure-resistant reaction vessel, 30 mols (5.59 kg) of2,2′-dihydroxybiphenyl, 30 mols (0.948 kg) of paraformaldehyde with apurity of 95%, 0.19 kg of paratoluenesulfonic acid and 10 liters ofethylene glycol dimethyl ether were charged, and the temperature wasraised to 130° C. with stirring. After the reaction was carried out at130° C. for 17 hours, the reaction mixture was cooled to 50° C. and thenput into 50 liters of water. The resin separated by putting said mixtureinto water was filtered off and then washed with water, followed bydrying to obtain 5.1 kg of a 2,2′-dihydroxybiphenyl-formaldehydecondensation resin (Condensation Product No. 2). The CondensationProduct No. 2 had a weight-average molecular weight of 5,400.

Production Example 3

Production of Condensation Product No. 3:

With reference to Production Example 1 disclosed in JapanesePre-examination Patent Publication (kokai) No. 57-164107, a polymerscale deposition preventive agent was produced.

Into a pressure-resistant reaction vessel, 250 mols (36.0 kg) of1-naphthol and 180 liters of 1N-NaOH aqueous solution (containing 180mols or 7.2 kg of NaOH) were charged, and the temperature was raised to70° C. with stirring. Next, to the reaction mixture, formaldehyde (19.75liters of 38 w/v % aqueous solution, 250 mols) was dropwise added over aperiod of 1.5 hours. During the addition, the internal temperature ofthe reaction vessel was controlled so as not to exceed 80° C. Then, thereaction mixture was cooled to 60° C. over a period of 3 hours with thestirring kept. Next, the temperature of the reaction mixture was raisedto 98° C. to carry out the reaction at 98° C. for 1.5 hours. Thereafter,the reaction mixture was cooled to obtain an alkaline solution of acondensation product (Condensation Product No. 3). The CondensationProduct No. 3 had a weight-average molecular weight of 2,400.

Production Example 4

Production of Condensation Product No. 4:

With reference to Coating Compound Synthesis 2 disclosed in JapanesePre-examination Patent Publication (kokai) No. 57-192413, a scaledeposition preventive agent was produced.

Into a pressure-resistant reaction vessel, 100 mols (12.6 kg) ofpyrogallol and 100 liters of water were charged, and the pyrogallol wasdissolved in the water. Next, to the solution obtained, 200 mols (21.2kg) of benzaldehyde and 300 mols (29.4 kg) of phosphoric acid wereadded, and the mixture thereof was reacted at 95° C. for 10 hours. As aresult, a water-insoluble reddish brown product was obtained. Thiswater-insoluble product was washed with ether, followed by extractionwith methanol to extract a methanol-soluble matter from thewater-insoluble product. Then, the methanol was removed from the extractby drying to obtain Condensation Product No. 4 (pyrogallol-benzaldehydecondensate), as a residue, which had a weight-average molecular weightof 4,500.

Production Example 5

Production of Condensation Product No. 5:

With reference to Production Example I disclosed in Japanese PatentPublication (kokoku) No. 59-16561, a scale deposition preventive agentwas produced.

Into a pressure-resistant reaction vessel, 100 mols (10.8 kg) ofm-phenylenediamine, 200 mols (22.0 kg) of resorcinol and 1.04 kg of 35%hydrochloric acid (10 mols as HCl) as a catalyst were charged, and thetemperature was raised to 305° C. Immediately after the mixture in thereaction vessel reached 305° C., it was cooled. The water vapor evolvedin the course of the raise in temperature and the reaction was removed,and the internal pressure was kept at 150 kPa or below. After cooling,the resulting m-phenylenediamine/resorcinol condensate was pulverized,followed by washing with water, filtering and drying, to obtainCondensation Product No. 5 which had a weight-average molecular weightof 4,000.

Production Example 6

Production of Condensation Product No. 6:

With reference to Production Example VI disclosed in Japanese PatentPublication (kokoku) No. 59-16561, a scale deposition preventive agentwas produced.

Into a pressure-resistant reaction vessel, 100 mols (10.9 kg) ofp-aminophenol and 0.99 kg of 30% hydrochloric acid (9.5 mols as HCl)were charged, and the temperature was raised to 169° C. Immediatelyafter the reaction mixture reached 169° C., 18 liters of xylene wasslowly added. The xylene was added so that the water formed during thecondensation reaction was removed as an azeotropic mixture. Next, thetemperature of the reaction mixture was raised to 222° C., and thereaction was carried out at 222° C. for 3 hours. The xylene-water mixedvapor evolved during the reaction was removed, and the internal pressurewas kept at 150 kPa or below. After the reaction was carried out for 3hours, the reaction mixture was cooled. The reaction product(Condensation Product No. 6) obtained was solid. Next, the reactionproduct was pulverized into fine particles, and thereafter washed withwater, followed by filtration and then drying to obtain the CondensationProduct No. 6 which had a weight-average molecular weight of 2,500.

Production Example 7

Production of Condensation Product No. 7:

With reference to Production Example 1 disclosed in JapanesePre-examination Patent Publication (kokai) No. 54-7487, a scaledeposition preventive agent was produced.

Into a reaction vessel, 200 mols (22.0 kg) of resorcinol was charged,and then heated in a nitrogen atmosphere. The temperature of resorcinolwas raised to 300° C., and the reaction was carried out at 300° C. for 8hours, followed by cooling. The solid self-condensed resorcinol thusobtained was pulverized to obtain Condensation Product No. 7 which had aweight-average molecular weight of 1,700.

Production Example

Production of Condensation Product No. 8:

(1) Synthesis of a 2,3-dihidoroxynaphthalene Dimer Compound

Into a flask having an inner capacity of 3 liters provided with a refluxcondenser, 1350 mL of methanol was charged and then 144 g (0.9 mol) of2,3-dihydoroxynaphthalene was dissolved therein. After the dissolution,the temperature was raised to 65° C., and 243 g (0.9 mol) of ferricchloride hydrate(FeCl₃·6H₂O) dissolved in 450 mL of methanol was addeddropwise to the solution obtained under reflux over 30 minutes. Afterthe addition, reaction was continued under reflux for 5 hours.Subsequently, the reaction solution was transferred into 4.5 liters of adiluted hydrochloric acid and then the resulting mixture was stirred for12 hours, to produce a dimer compound of 2,3-dihydroxynaphthalene. Thereaction solution thus obtained was filtered to remove the solvents, andthereafter the residual matter was washed with two liters of pure waterfor two hours. The solution was filtered again to remove the ferricchloride hydrate(FeCl₃.6H₂O).

The dimer compound of 2,3-dihydroxynaphthalene obtained was dried in adryer at 40° C.

(2) Into a 3 liter-flask provided with a reflux condenser, one liter ofpure water was charged, and then 5 g of sodium hydroxide and 50 g of the2,3-dihydroxynaphthalene dimer compound obtained as above were charged.Subsequently, after the temperature was raised to 70° C., 12.75 g of 37%aqueous formaldehyde solution dissolved in 237.3 g of distilled water,was added dropwise over 30 minutes. After the addition, reaction wascontinued at the same temperature for five hours, and then thetemperature was raised to 95° C. and reaction was continued for furthertwo hours, thereby Condensation Product No. 8 being obtained.Incidentally, the reactions were all carried out in N₂ atmospheres.

After the completion of the reactions, Condensation Product No. 8 wascooled to 25° C., and then preserved in an N₂ atmosphere. Theweight-average molecular weight was 22,000.

Production Example 9

Production of Condensation Product No. 9:

Into a reaction vessel having an inner capacity of 2 liters providedwith a reflux condenser, a mixed solvent of methanol (450 g) with water(450 g) was charged and subsequently 100 g of α-naphthoquinone and 10 gof sodium hydroxide were charged. Then, the internal temperature of thereaction vessel was raised to 50° C. and the mixture in the reactionvessel was reacted at 50° C. for 24 hours, followed by cooling the sameto room temperature. Thus, a solution of Condensation Product No. 9 wasobtained. The Condensation Product No. 9 had a weight-average molecularweight of 3,000.

Production Example 10

Production of Condensation Product No. 10:

In a 20 L internal volume reaction vessel having a reflux condenser, 1.5kg of 1-naphthol and 7.5 L of toluene were put, and the mixture obtainedwas heated with stirring until the toluene became refluxed. Under refluxat this temperature, 930 ml of sulfur monochloride was added dropwiseover a period of 6 hours, and thereafter the mixture obtained was keptfor 1 hour at that temperature. After the reaction mixture was cooled, 5L of hexane was added with stirring to cause the reaction product toprecipitate. Thereafter, the reaction product was filtered, and thendried to obtain Condensation Product No. 10. The Condensation ProductNo. 10 had a weight-average molecular weight of 1,200.

Production Example 11

Production of Condensation Product No. 11:

In a 20 L internal volume reaction vessel having a reflux condenser, 6.7L of water, 1,786 g (9.5 mols) of 6-hydroxy-2-naphthoic acid, 55 g (0.5mol) of resorcinol and 620 g (15.5 mols) of NaOH were put, andthereafter the mixture obtained was heated to 50° C. with stirring. Atthe time it reached 50° C., 1.0 L of an aqueous 30 w/v % formaldehydesolution (formaldehyde: 10 mols) was added dropwise over a period of 1hour. During the addition, the internal temperature of this reactionvessel was so controlled not to become higher than 55° C. Next, thereaction mixture thus obtained was heated to 85° C., and was allowed toreact at 85° C. for 3 hours. Thereafter, the reaction mixture obtainedwas cooled to obtain an alkaline solution of a condensation product(Condensation Product No. 11). The Condensation Product No. 11 had aweight-average molecular weight of 2,200.

Preparation of First Coating liquid

Preparation of first coating liquid Nos. 101-126:

Using a conjugated π bond compound, pH adjuster and solvent shown inTable 1, first layer forming first coating liquids were so prepared asto meet the conditions shown in Table 1 [conjugated π bond compound (A),auxiliary agent (B), pH adjuster, (A)/(B) weight ratio, (A)+(B) totalconcentration, solvent composition, and pH]. In the table, the coatingliquid No. 102 is a comparative coating liquid containing a polymerscale preventive agent in a low concentration, to be used for spraycoating.

Preparation of coating liquid Nos. 127-131:

The following compounds I to V were used as a conjugated π bondcompound.

I: phenanthrene-1,2-quinone

II: flavonol

III: phenothiazine

IV: 1,8-diaminonaphthalene

V: anthraquinoneacrydone

Using a compound above, pH adjuster and solvent shown in Table 1, firstcoating liquids were so prepared as to meet the conditions shown inTable 2 [conjugated π bond compound (A), auxiliary agent (B), pHadjuster, (A)/(B) weight ratio, (A)+(B) total concentration, solventcomposition, and pH]. In the following table, the condensation productis simply called “CP”. For example, “CP 9” stands for “CondensationProduct No. 9”.

TABLE 1 Coat- Conju- ing First gated (A)/ liquid coat- π (B) con- Coat-ing bond (wei- cen- ing liq- com- ght tra- liq- uid pound Auxiliary pHra- tion uid No. (A) agent (B) adjuster tio) (wt. %) Solvent pH 101 CP9none NaOH — 5 water 12.5 102 CP9 colloidal NaOH 100/ 0.5 water 10.5silica 100 103 CP1 none NaOH — 3.5 water/ 9.5 methanol 60/40 104 CP2none KOH — 3.5 water 13.0 105 CP3 none NaOH — 2.5 water 12.5 106 CP4none ethylene — 5 water/ 9.0 diamine methanol 70/30 107 CP5 none NaOH —4 water 13.0 108 CP6 none KOH — 4 water 12.0 109 CP7 none nitric — 4water 4.5 acid 110 CP8 none NaOH — 4 water 12.5 111 CP9 none ethylene —3.5 water 12.0 diamine 112 CP10 none NaOH — 5 water 12.0 113 CP11 noneNaOH — 5 water 12.5 114 CP10 none none — 5 N-methyl- — 2- pyrrol- idone

TABLE 2 Conju- First gated (A)/ coat- π Aux- (B) Coating Coat- ing bondili- (wei- liquid ing liq- com- ary ght concen- liq- uid pound agent pHra- tration uid No. (A) (B) adjuster tio) (wt. %) Solvent pH 115 I noneethylene — 5 water 12.5 diamine 116 II none NaOH — 5 water 12.5 117 IIInone none — 5 methanol — 118 IV none none — 5 methanol — 119 V none none— 5 N-methyl-2- — pyrrolidone

Preparation of Second Coating liquid

Preparation of second coating liquid Nos. 201-218:

Using a pH adjuster and a solvent shown in Tables 3 and 4, coatingliquids containing a dye and/or a pigment (second coating liquids) wereso prepared as to meet the conditions shown in Tables 3 and 4 [dyesand/or pigments, the concentration thereof, solvent, pH adjuster, andpH]. In the Table 3, the coating liquid No. 202 is a comparative coatingliquid containing a polymer scale preventive agent in a relatively lowconcentration, to be used for spray coating.

TABLE 3 Coat- Dyes Concen- Coat- ing and/or tration ing liquid pigmentsof (A) pH liquid No. (A) (wt. %) Solvent adjuster pH 201 C.I. Acid 5water phytic acid 2.0 Black 2 202 C.I. Acid 0.4 water phytic acid 2.0Black 2 203 C.I. Acid 2 water/ ethylene 8.0 Green 3 methanol diamine70/30 204 C.I. 4 water NaOH 8.0 Reactive Blue 5 205 C.I. 8 water NaOH9.0 Reactive Black 1 206 C.I. Acid 5 water phosphoric 4.0 Red 51 acid207 C.I. 6 water sulfuric 4.0 Direct acid Blue 41 208 C.I. 3 water/ KOH9.5 Basic acetone Orange 14 80/20 209 C.I. 5 water KOH 9.5 Basic Red 9

TABLE 4 Coat- Dyes Concen- Coat- ing and/or tration ing liquid pigmentsof (A) pH liquid No. (A) (wt. %) Solvent adjuster pH 301 C.I. 3 watertannic acid 3.0 Basic Blue 3 302 C.I. Acid 4 water tannic acid 3.0 Black2 303 C.I. 4 water phytic acid 2.0 Direct Blue 106 304 C.I. 5 waterphytic acid 2.0 Direct Blue 86 305 C.I. Acid 5 water phytic acid 2.0Violet 31 306 C.I. 4 water sulfuric 2.0 Direct acid Black 17 307 C.I. 4water phosphoric 2.0 Direct acid Brown 95 308 C.I. 5 water pyrophos- 2.0Basic phoric acid Black 2 309 C.I. Acid 6 water tannic acid 4.0 Blue 59

Example 1

FIG. 2 schematically illustrates the arrangement of a polymerizationapparatus. In respect to a polymerization vessel, the same elements asin FIG. 1 are denoted with the same numerals. The following experimentswere made using a polymerization apparatus shown in FIG. 2. In FIG. 2, a2 m³ internal volume polymerization vessel 1 made of SUS 316L stainlesssteel is equipped with a stirrer 21 having stirring blades 20 (astirring motor is not shown), a heating-cooling jacket 2, a manhole 22,a baffle 23 and other fittings (not shown) usually providing forpolymerization vessels for polymerizing vinyl chloride. A line 24connected to the upper part of the polymerization vessel 1 is a line forcharging materials. To the line 24, branch lines such as a vinylchloride monomer (VCM) charging line 24 a, a catalyst solution chargingline 24 b, a suspending agent charging line 24 c and a pure-watercharging line 24 d are connected as shown in FIG. 2. This charging lines24 and 24 a-24 d are provided with valves V1, V2, V3, V4 and V5 at thepositions shown in the drawing. A line 25 also connected to the upperpart of the polymerization vessel 1 is provided in order to evacuate theinside of the polymerization vessel 1 and to recover monomers, and isled to a gas holder 27 through a line 26 branched from the line 25. Amonomer recovery line 28 is led out of the gas holder 27, and a line 29led out of the gas holder 27 is connected to the line 25 so as to beused in pressure equalization described later. These lines 25, 26, 28and 29 are provided with valves V6, V7, V8, V9, V10, V11, V12 and V13.The line 26 is branched into a line 26 a provided with a vacuum pump 30so that monomers can be recovered and a line 26 b with no pump, andthereafter the branched lines are joined together to form a single linewhich is connected to the gas holder 27. To the upper part of thepolymerization vessel 1, a line 31 is also connected in order to washthe inside of the polymerization vessel with water. The line 31 isprovided with valves 14 at the position shown in the drawing and has anozzle 32 at the end introduced inside the vessel. To the upper part ofthe polymerization vessel 1, a first coating liquid feed line 34 and asecond coating liquid feed line 35 are connected to a coating liquidfeed line 33 through valves as shown in the drawing. Further, to theline 33 a steam feed line 36 is connected via a valve. The line 33 isprovided at its end located inside the vessel with a coating ring 4 towhich coating nozzles 3 a, 3 b are attached. These lines are providedwith valves V15, V16, V17 and V18 at the positions shown in the drawing.The steam feed line 36 is provided with a valve 19 at the position shownin the drawing. To the bottom of the polymerization vessel 1, a line 37is connected, which is branched into a line 38 a through which polymerslurry is led a blow-down tank and a line 38 b through which the coatingliquids or washing water is discharged. The lines 38, 38 a and 38 b areprovided with valves V20, V21 and V22 at the positions shown in thedrawing.

The coating liquids used in each experiment are shown by number in Table5. The coating liquids were coated previously on the polymerizationvessel inner wall surfaces and others in the manner as described below,followed optionally by drying to form a coating film. In thepolymerization vessel, vinyl chloride monomers were polymerized in themanner as described below.

(1) Coating and drying:

The coating film is formed on the inner wall surfaces and others of thepolymerization vessel of the polymerization apparatus shown in FIG. 2,by a method of a), b), c) or d) below. Methods a), b) and c) are methodsof comparative examples. In the initial stage of each method, all of thevalves are closed.

a) One-stage spray coating and drying:

Hot water is passed through the jacket 2 to keep the polymerizationvessel 1 inner wall surfaces heated to a temperature of 70° C. (Time forpreheating with the jacket: 10 minutes). The valves V17, V16, V15, V20and V22 are opened, and the first coating liquid containing a polymerscale preventive agent is coated at a flow rate of 5 L(liter)/min for1.5 minutes. The valves V17, V16, V15, V20 and V22 are closed, and thenthe valves V6, V8, V13, and V9 are opened, where the vacuum pump 30 isactuated to evacuate the inside to −700 mmHg and the wet coating isdried (drying is necessary; drying time: 25 minutes) to form a coatingfilm. Thereafter, the vacuum pump is stopped and the valves V8, V13, andV9 re closed. Next, the valves V7 and V10 are opened to make theinternal pressure of the polymerization vessel 1 equal to the internalpressure of the gas holder 27. Thereafter, the valves V6, V7 and V10 areclosed. The feeding of hot water to the jacket 2 is stopped.

b) Two-stage spray coating and drying:

Hot water is passed through the jacket 2 to keep the polymerizationvessel 1 inner wall surfaces heated to a temperature of 70° C. (Time forpreheating with the jacket: 10 minutes). The valves V17, V16, V15, V20and V22 are opened, and the coating liquid containing a polymer scalepreventive agent (for under coating) is coated at a flow rate of 5 L/minfor 1.5 minutes. The valves V17, V16, V15, V20 and V22 are closed, andthen the valves V6, V8, V13, and V9 are opened, where the vacuum pump 30is actuated to evacuate the inside to −700 mmHg and the wet coating isdried (drying is necessary; drying time: 25 minutes) to form a firstlayer. Thereafter, the vacuum pump is stopped and the valves V8, V13,and V9 are closed. Next, the valves V7 and V10 are opened to make theinternal pressure of the polymerization vessel 1 equal to the internalpressure of the gas holder 27. Thereafter, the valves V6, V7 and V10 areclosed. Next, the valves V18, V16, V15, V20 and V22 are opened, and thecoating liquid containing a polymer scale preventive auxiliary agent(for top coating) is coated on the above first layer at a flow rate of 5L/min for 1.5 minutes. The valves V18, V16, V15, V22 and V20 are closed,and then the valves V6, V8, V13, and V9 are opened, where the vacuumpump 30 is actuated to evacuate the inside to −700 mm Hg and the wetcoating is dried (drying is necessary; drying time: 25 minutes) to forma second layer. Thereafter, the vacuum pump is stopped and the valvesV8, V13, and V9 are closed. Next, the valves V7 and V10 are opened tomake the internal pressure of the polymerization vessel 1 equal to theinternal pressure of the gas holder 27. Thereafter, the valves V6, V7and V10 are closed. The feeding of hot water to the jacket 2 is stopped.

c) One-stage steam coating (simultaneous drying):

Hot water is passed through the jacket 2 to keep the polymerizationvessel 1 inner surfaces heated to a temperature of 70° C. (Time forpreheating with the jacket: 10 minutes). The valves V19, V22, V20, V15and V16 are opened, and 4 kgf/cm²·G (143° C.) of steam is blown into thepolymerization vessel at a flow rate of 240 kg/Hr for 3 minutes. Afterthe inside of the vessel is pre-heated, the valve V17 is opened, and thecoating liquid containing a polymer scale preventive agent is coated anddried simultaneously at a flow rate of 0.2 L/min for 2 minutes whileutilizing the steam as a carrier. Thereafter, the valves V19, V22, V20,V15, V16 and V17 are closed. The feeding of hot water to the jacket 2 isstopped.

d) Two-stage steam coating (simultaneous drying):

(1) Coating and drying

Hot water is passed through the jacket 2 to keep the polymerizationvessel 1 inner wall surfaces heated to a temperature of 70° C. (Time forpreheating with the jacket: 10 minutes). The valves V19, V22, V20, V15and V16 are opened, and 4 kgf/cm²·G (143° C.) of steam is blown into thepolymerization vessel 1 at a flow rate of 240 kg/Hr for 3 minutes. Afterthe inside of the vessel is pre-heated, the valve V17 is opened, and thefirst coating liquid containing a polymer scale preventive agent (forunder coating) is coated and dried simultaneously at a flow rate of 0.2L/min for 2 minutes while utilizing the steam carrier, to form a firstlayer. Thereafter, the valve 17 is closed. Then the valve 18 is opened,and the coating liquid containing an auxiliary agent (for top coating)is coated and dried simultaneously at a flow rate of 0.2 L/min for 1minute while utilizing the steam carrier, to form a second layer on thefirst layer. Thereafter, the valves V19, V22, V20, V15, V16 and V18 areclosed. The feeding of hot water to the jacket 2 is stopped.

(2) Second water washing for inside of the vessel:

The valves V14, V20, V22, V6, V7 and V10 are opened to wash the insideof the polymerization vessel with water, and the wash water isdischarged to a waste water tank. The valves V14, V20 and V22 areclosed.

The time for washing with water is four (4) minutes when the method a)or b) is used, and it is one (1) minute when the method c) or d) isused.

(3) Charging:

The valves V1, V2 and V3 are opened, and 200 parts by weight of purewater, 0.022 part by weight of partially saponified polyvinyl alcoholand 0.028 parts by weight of hydroxymethyl cellulose are charged intothe polymerization vessel 1. The valves V1, V2, V3, V6, V7 and V10 areclosed.

Next, the valves V1 and V5 are opened, and 100 parts by weight of vinylchloride monomer (VCM) is charged. Then the valve V5 is closed. Next,with the charged materials being stirred, the valve V4 is opened, and0.03 part by weight of t-butyl peroxyneodecanate is charged. Then thevalves V1 and V4 are closed.

(4) Polymerization:

Hot water is passed through the jacket 2 to raise the temperature whilestirring the materials charged. At the time the internal temperature hasreached 52° C., cooling water is passed through the jacket 2 to maintainthe internal temperature at 52° C., where the polymerization is carriedout. At the time the internal pressure has dropped to 5 kgf/cm², thepolymerization is terminated.

(5) Gas discharging:

The valves V6, V8, V12 and V9 are kept open, and gas is discharged tothe gas holder 27 until the internal pressure returns to substantiallythe atmospheric pressure. Thereafter, the valves V12, V8 and V9 areclosed. Then the valves V11 and V10 are opened, and monomers recoveredin the gas holder 27 is sent to the step of recovering the VCM throughline 28. Thereafter, the valves V11 and V10 are closed.

(6) Pressure equalization:

The valves V7 and V10 are opened, and the internal pressure of thepolymerization vessel 1 and the internal pressure of the gas holder 27are made equal (pressure equalization).

(7) Slurry withdrawing:

The valves V20 and V21 are opened, and polymerization slurry iswithdrawn out of the vessel to the blow-down tank (not shown). Thepolymerization slurry withdrawn to the blow-down tank is thereafterdehydrated and dried to become a vinyl chloride polymer product.

(8) Vessel-inside first washing:

The valve V14 is opened. The inside of the polymerization vessel iswashed with water, and the wash water is sent to the blow-down tank.Thereafter, the valves V14, V20, V21, V6, V7 and V10 are closed. Duringthis washing of the inside of the vessel, hot water is passed throughthe jacket 2 to keep the temperature of the polymerization vessel wallsurfaces at 70° C.

The operation from the (1) coating and drying up to the (8) firstwashing after completion of polymerization is set as one batching. Thelike operation was repeated by the number of batching as shown in Table6.

<Evaluation>

Time required to form coating films

The time taken for the formation of coating films in Examples andComparative Examples is shown in Table 5.

Measurement of the amount of polymer scale deposited

In each experiment, after the final batching was completed, polymerscale built-up at the liquid-phase portion in the polymerization vesseland polymer scale built-up on the surfaces of stirring blades andbaffles and on and in the vicinity of the boundary between the gas-phaseportion and the liquid-phase portion were determined in the followingway.

The scale deposited in an area of 10 cm×10 cm at a surface to bemeasured was scraped off with a spatula as completely as can beconfirmed with the naked eye, and then the scraped scale was weighed ona balance. The measured value was multiplied by 100 to obtain the amountof the deposited polymer scale per area of 1 m². The results are givenin Table 7.

Measurement of fish eyes

Fish eyes produced when a polymeric product obtained at the finalbatching in each experiment is formed into sheet, were measured by themethod below. The results are given in Table 8.

A hundred (100) parts by weight of a polymer obtained, 50 parts byweight of dioctyl phthalate (DOP), 1 part by weight of dibutyltindilaurate, 1 part by weight of cetyl alcohol, 0.25 part by weight oftitanium oxide and 0.05 part by weight of carbon black were mixed. Theresulting mixture was kneaded at 150° C. for 7 minutes with 6 inchrolls, and then formed into a sheet 0.2 mm thick. The obtained sheet wasexamined for the number of fish eyes per 100 cm² by light transmission.

Measurement of luminosity index (L value)

Measurement of luminosity index (L value) of a sheet formed from apolymer obtained in each experiment was carried out, according to themethod below. The results are given in Table 8.

A hundred (100) parts by weight of an obtained polymer, 1 part by weightof a dibutyltin laurate stabilizing agent (TS-101, product of AkisimaChemical Co.) and 0.5 part by weight of a cadmium organic complexstabilizing agent (C-100J, product of Katsuta Kako Co.), and 50 parts byweight of dioctyl phthalate as a plasticizer were kneaded at 160° C. for5 minutes with a twin roll mill, and then formed into a sheet 1 mmthick. Subsequently, this sheet was placed in a molding frame measuring4×4×1.5 cm, heated at 160° C. under a pressure of 65 to 70 kgf/cm² toprepare a test specimen. This test specimen was measured for luminosityindex L in the following way.

First, the stimulus value Y of XYZ color system is determined by thephotoelectric tristimulus colorimetry using the standard light C,photoelectric colorimeter (Color measuring color difference meter ModelZ-1001DP, product of Nippon Denshoku Kogyo K.K.) in accordance with JISZ 8722. As the geometric condition of illumination and light reception,the condition defined in section 4.3.1 of JIS Z 8722 is adopted. Next,from the stimulus value Y obtained, the L value is calculated based onthe Hunter's color difference equation: L=10Y^(½) described in JIS Z8730 (1980). The greater the value of L, the higher the whiteness isevaluated, namely, the slighter the initial discoloration is evaluated.

Examination of Colored particles:

A mixture of 100 parts by weight of the polymer obtained in eachexperiment after the final batching was completed, 2 parts by weight ofa stabilizer TVS N-2000E (available from Nitto Kasei Co., Ltd.) and 20parts by weight of a plasticizer dioctyl phthalate was thoroughlykneaded and thereafter put in a molding frame of 160 mm×130 mm×3 mm, andwas subsequently pressure-molded at a temperature of 175° C. and apressure of 35 kg/cm² to obtain a sample for examination. Samples thusobtained were examined visually on the number of colored particles. Theresults are shown in Table 8.

Measurement of contact angles to water after immersion in vinyl chloridemonomer:

Contact angles to water of the surface of the first layer obtained afterthe first coating liquid was coated and the surface of the second layerobtained after the second coating liquid was coated were also determinedin the following way.

a-1) Preparation of samples for one-stage spray coating:

Six test pieces of 20 mm×20 mm×thickness 1 mm made of stainless steel(SUS 316L) are stuck at equal intervals along the circumference in thevicinity of a gas-liquid boundary surface of the inner wall of thepolymerization vessel. Thereafter, according to the coating process a)described above, a coating film is formed by one-stages pray coating.Thereafter, the test pieces are taken out of the polymerization vessel.These are designated as test pieces of one-stage spray coating film.

a-2) Preparation of samples for two-stage spray coating:

i) Preparation of samples for first-layer in two-stage spray coating:

Test pieces are stuck at six positions on the inner wall surface of thepolymerization vessel in the same manner as in a-1). Thereafter, thecoating process b) is followed, but only a first layer is formed in thepolymerization vessel. Thereafter, the test pieces are taken out of thepolymerization vessel. These are designated as test pieces of two-stagespray coating first layer.

ii) Preparation of samples for second-coated coating film in two-stagespray coating:

Test pieces are stuck at six positions on the inner wall surface of thepolymerization vessel in the same manner as in a-1). Thereafter,according to the coating process b), a first layer is formed in thepolymerization vessel and a second layer is further formed in thepolymerization vessel. Thereafter, the test pieces are taken out of thepolymerization vessel. These are designated as test pieces of two-stagespray coating film.

a-3) Preparation of samples for one-stage steam coating: Test pieces arestuck at six positions on the inner wall surface of the polymerizationvessel in the same manner as in a-1). Thereafter, according to thecoating process c), a coating film is formed in the polymerizationvessel. Thereafter, the test pieces are taken out of the polymerizationvessel. These are designated as test pieces of one-stage steam coatingfilm.

a-4) Preparation of samples for two-stage steam coating:

i) Preparation of samples for first-layer in two-stage steam coating:

Test pieces are stuck at six positions on the inner wall surface of thepolymerization vessel in the same manner as in a-1). Thereafter, thecoating process d) is followed, but only a first layer is formed in thepolymerization vessel. Thereafter, the test pieces are taken out of thepolymerization vessel. These are designated as test pieces of two-stagesteam coating first layer.

ii) Preparation of samples for second-coated coating film in two-stagesteam coating:

Test pieces are stuck at six positions on the inner wall surface of thepolymerization vessel in the same manner as in a-1). Thereafter,according to the coating process d), a first layer is formed and asecond layer is further formed in the polymerization vessel. Thereafter,the test pieces are taken out of the polymerization vessel. These aredesignated as test pieces of two-stage steam coating film.

Immersion of coated test pieces in vinyl chloride monomer:

A 2 liter pressure-resistant container is used which has a stirrer andon the inner wall surface of which grooves are provided to which thetest pieces can be fixed. The test pieces on which the coating filmshave been formed in the manner as described above are fitted to thegrooves of the pressure-resistant container to attach the test pieces tothe inner wall surface of the container in such a way that their coatedsurfaces face inward (appear on the inner wall surface).

Into the pressure-resistant container to the inner wall surface of whichthe test pieces have been attached in this way, 600 g of water and 600 gof vinyl chloride monomer are charged, thus the test pieces are immersedin these contents. Next, the contents in the pressure-resistantcontainer are heated to 50° C. with stirring, and are continued beingstirred for 1 hour at the temperature maintained at 50° C. Next, thecontents are cooled to room temperature. Simultaneously, recovery of thevinyl chloride monomer present in the pressure-resistant container isstarted. After the recovery of the vinyl chloride monomer is completed,the water is withdrawn from the inside of the pressure-resistantcontainer. Next, the test pieces are detached from the inner wallsurface of the pressure-resistant container, and then dried in a vacuumdryer at a drying temperature of 50±1° C. for a drying time of 2 hours.

After the test pieces have been dried, they are moved into a desiccator,and are left therein at 20° C. for 24 hours. Thus, test pieces formeasuring the contact angles to water are obtained.

Measurement of contact angles to water:

Contact angles to water on the test pieces thus obtained were measuredin air in a 20° C. room by the droplet method, using a contact anglemeter (Model CA-A, manufactured by Kyowa Kaimen Kagaku K.K.). Thecontact angles were measured at five spots for each test piece, and anaverage value of the measurements on six test pieces was determined,which was regarded as the contact angles to water of the coating filmsobtained in the experiment.

TABLE 5 Spray coating Steam coating a) One b) Two c) One d) Two stagestages stage stages Jacket pre-heating time (min) 10.0 10.0 10.0 10.0Steam pre-heating time (min) 0 0 3.0 3.0 First-stage coating time (min)1.5 1.5 2.0 2.0 First-stage drying time (min) 25.0 25.0 0 0 Second-stagecoating time (min) 0 1.5 0 1.0 Second-stage drying time (min) 0 25.0 0 0Water washing time (min) 4.0 4.0 1.0 1.0 (second washing) Total time(min) 40.5 67.0 16.0 17.0

TABLE 6 First stage Second stage Ex- Coat- Coat- Contact peri- Coatingfilm ing Contact ing angle ment forming liquid angle after liquid afterNo. conditions No. coating (°) No. coating(°) 101 d) Steam, 2 stages 101100 201 40 102* c) Steam, 1 stage 101 100 none — 103* a) Spray, 1 stage102 40 none — 104* a) Spray, 1 stage none — 201 40 105* b) Spray, 2stages 102 40 202 40 106 d) Steam, 2 stages 101 100 203 45 107 d) Steam,2 stages 101 100 204 40 108 d) Steam, 2 stages 101 100 205 35 109 d)Steam, 2 stages 101 100 206 35 110 d) Steam, 2 stages 101 100 207 40 111d) Steam, 2 stages 101 100 208 50 112 d) Steam, 2 stages 101 100 209 50113 d) Steam, 2 stages 103 115 301 35 114 d) Steam, 2 stages 104 95 30235 115 d) Steam, 2 stages 105 90 303 25 116 d) Steam, 2 stages 106 85304 40 117 d) Steam, 2 stages 107 110 305 40 118 d) Steam, 2 stages 108125 306 40 119 d) Steam, 2 stages 109 90 307 35 120 d) Steam, 2 stages110 85 308 25 121 d) Steam, 2 stages 111 100 309 30 122 d) Steam, 2stages 112 100 302 30 123 d) Steam, 2 stages 113 105 302 40 124 d)Steam, 2 stages 114 100 302 45 125 d) Steam, 2 stages 115 100 302 45 126d) Steam, 2 stages 116 105 302 45 127 d) Steam, 2 stages 117 130 302 50128 d) Steam, 2 stages 118 125 302 55 129 d) Steam, 2 stages 119 110 30250 *:Comparative examples

TABLE 7 Scale build-up (g/m²) On and in Exper- Number Liquid thevicinity iment of phase of gas-liquid Stirring No. batching portionboundary surface blades Baffles 101 300 0 0 0 0  102* 300 0 105 17 19 103* 300 0 0 125 135  104* 10 6 110 215 230  105* 300 0 0 105 110 106300 0 1 1 2 107 300 0 1 1 1 108 300 0 1 1 2 109 300 0 0 1 2 110 300 0 01 1 111 300 0 0 1 2 112 300 0 0 1 2 113 300 0 0 0 0 114 300 0 0 0 0 115300 0 0 0 0 116 300 0 0 0 0 117 300 0 0 0 0 118 300 0 0 0 0 119 300 0 00 0 120 300 0 0 0 0 121 300 0 0 0 0 122 300 0 0 0 0 123 300 0 0 0 0 124300 0 0 0 0 125 300 0 0 2 2 126 300 0 0 2 2 127 300 0 0 3 4 128 300 0 02 2 129 300 0 0 2 2 *Comparative examples

TABLE 8 Scale Build-up and Product Quality Experiment Fish eyesLuminosity index Colored particles No. (number) (value L) (number) 101 173.0 2  102* 13 72.0 44  103* 61 72.0 73  104* 82 71.0 80  105* 16 72.051 106 3 73.0 8 107 3 73.0 6 108 3 73.0 6 109 4 73.0 7 110 3 73.0 5 1113 73.0 7 112 3 73.0 8 113 1 73.0 3 114 1 73.0 2 115 2 73.0 3 116 2 73.03 117 2 73.0 4 118 2 73.0 4 119 2 73.0 3 120 1 73.0 3 121 1 73.0 3 122 173.0 2 123 2 73.0 3 124 1 73.0 3 125 4 73.0 9 126 3 73.0 10 127 4 73.0 9128 5 73.0 8 129 4 73.0 10 *Comparative examples

What is claimed is:
 1. A process for producing a polymer by polymerizingin a polymerization vessel a monomer having an ethylenic double bond,wherein said polymerization vessel has a polymer scale preventivecoating film on its inner wall surfaces and other surfaces with whichthe monomer comes into contact during polymerization; said coating filmcomprising a first layer formed on said inner wall surfaces and othersurfaces and a second layer formed on the first layer; said first layerbeing formed by coating a first coating liquid containing a conjugated πbond-containing compound selected from the group consisting of anaromatic compound having 5 or more conjugated π bonds and a heterocycliccompound having 5 or more conjugated π bonds by means of steam as acarrier, and said second layer being formed by coating a second coatingliquid on the first layer by means of steam as a carrier; and saidsecond layer containing a member selected from the group consisting ofdyes and pigments and having a surface having a contact angle to waterof less than 60° after its surface has been kept in contact with asolution of mixture of water and a vinyl chloride monomer in a weightratio of 1:1 at 50° C. for 1 hour.
 2. The process of claim 1, whereinsaid contact angle to water ranges from 10 to 55°.
 3. The process ofclaim 1, wherein the first layer having been formed, has a surfacehaving a contact angle to water of 60° or more after the surface hasbeen kept in contact with a solution of a mixture of water and a vinylchloride monomer in a weight ratio of 1:1 at 50° C. for 1 hour.
 4. Theprocess of claim 1, wherein said conjugated π bond-containing compoundcontained in the first coating liquid is an aromatic compoundcondensation product having a weight-average molecular weight of 500 ormore.
 5. The process of claim 4, wherein said aromatic compoundcondensation product has a weight-average molecular weight of 500 to70,000.
 6. The process of claim 4, wherein said aromatic compoundcondensation product is selected from the group consisting of aldehydecompound/aromatic hydroxyl compound condensation products,pyrogallol/acetone condensation products, polyhydric phenolself-condensation products, polyhydric naphthol self-condensationproducts, aromatic amine compound condensation products, quinonecompound condensation products, and sulfide compounds of aromatichydroxyl compounds.
 7. The process of claim 4, wherein said aromaticcompound condensation product is an aldehyde compound/aromatic hydroxylcompound condensation product or a quinone compound condensationproduct.
 8. The process of claim 1, wherein said first coating liquid isa solution containing a compound selected from the group consisting ofpyrogallol/acetone condensation products, polyhydric phenolself-condensation products and polyhydric naphthol self-condensationproducts in water or a mixed solvent of water with a hydrophilic organicsolvent miscible with water, and having a pH of 2.0 to 6.5.
 9. Theprocess of claim 1, wherein said first coating liquid is a solutioncontaining a compound selected from the group consisting of condensationproducts of aldehyde compound/aromatic hydroxyl compound, condensationproducts of an aromatic amine compound, and condensation products of aquinone compound in water or a mixed solvent of water with a hydrophilicorganic solvent miscible with water, and having a pH of 7.5 to 13.5. 10.The process of claim 1, wherein said first coating liquid contains theconjugated π bond-containing compound in a concentration ranging from1.0 to 25.0% by weight.
 11. The process of claim 1, wherein said dyeand/or pigment is selected from the group consisting of azo dyes andpigments, anthraquinone dyes and pigments, indigoid dyes and pigments,phthalocyanine dyes and pigments, carbonium dyes and pigments,quinoneimine dyes, methine dyes, quinoline dyes, nitro dyes,benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes and pigments,perinone dyes, sulfide dyes, fluorescent dyes, azoic dyes, and reactivedyes.
 12. The process of claim 1, wherein said dye and/or pigment isselected from the group consisting of azo dyes and pigments,anthraquinone dyes and pigments, indigoid dyes and pigments,quinoneimine dyes, and naphthoquinone dyes.
 13. The process of claim 1,wherein said dye and/or pigment is selected from the group consisting ofacid dyes, direct dyes and basic dyes.
 14. The process of claim 1,wherein the second coating liquid contains said dye and pigment in aconcentration ranging from 0.01 to 20% by weight in water or a mixedsolvent of water with a hydrophilic solvent miscible with water.
 15. Theprocess of claim 1, wherein both said steam used in application of saidfirst coating liquid and said steam used in application of said secondcoating liquid have a temperature of 120 to 260° C. and a pressure of 2to 35 kgf/cm² G.
 16. The process of claim 15, wherein said steams have atemperature of 130 to 200° C. and a pressure of 2.8 to 20 kgf/cm² G. 17.The process of claim 1, wherein in both applications of said firstcoating liquid and second coating liquid, the coating liquid (L) and thesteam (G) is mixed in a ratio (L/G) of from 0.005 to 0.8 in terms offlow rate ratio on the basis of weight.
 18. The process of claim 17,wherein said ratio of L/G is in a range of 0.01 to 0.2.